ANON, YOU ARE A GENIUS!

You are absolutely correct, and I think it's all very much tied to the earlier conversation in the bar, where Nick asks Rio for advice on how to get Beth to do what he wants and Rio gives (imo intentionally) bad advice that is only partially true (Rio dismisses the route of romancing Beth, as if he hasn't specifically seen amazing results from telling her "I think you could be someone" and "Nah, I love it").

The scene ends with this exchange, where Rio talks about how Nick always wants what he has (which, importantly, is in present tense, because Rio still currently considers Beth "his"):

Nick tells Rio—while literally taking his food—that he always gets what's Rio's too, basically promising that he's going to "win" Beth.

In reaction to this conversation, Rio shows up at Sweet P's and inserts himself into Beth's business, pulling the chord between them tighter, but pissing Beth off in the process.

At the end of the episode, after Dave and Phoebe give her the file and indicate that they are going after Nick, not Rio, Beth decides to join City Council, gifting Nick a bottle of alcohol to thank him for helping her get the strip club back up and running and to announce that she is running. When he asks what made her change her mind, she says, "You," but we know it's a lie since it's immediately following a shot of her looking over the evidence with a photo of Nick giving a speech and a flyer to his gardening initiative. She didn't make her decision based on Rio's insertion into Sweet P's or Nick's favors. She's doing it in her own self-interest, namely, to flip on Nick and try and put him away.

However, Nick doesn't see that, and he tries to turn the moment into something less strictly professional when he invites Beth to drink with him:

Beth says she hasn't earned it yet (which I love because it's in contrast to how Rio makes her earn everything, and how she's sought him out to celebrate after her success in legitimately earning it like in 4.01) and Nick promises her she's going to win, and she tells him to, "Share it with someone who already has."

We then get this lingering shot of Nick standing alone, left behind, looking disappointed and even irritated that he can't seem to crack what works with Beth and that he's making no headway with her—at least, not in the way he wants. He definitely seems interested in pursuing her romantically/sexually, less because of genuine interest, and more because he seems to want to take something away from Rio.

He regifts the bottle to Rio, "the winner," because ultimately he realizes Rio is right and he failed in his task to woo Beth. He pretends, though, capitalizing on Rio "pulling her ponytail" by yanking control of Sweet P's from her hands, suggesting that the very move Rio made in order to keep Beth close is actually the one that pushed her away—and toward Nick.

Phoebe and Dave gave Beth the file (that's what she was looking at on the bench in the back of Sweet P's) and earlier in the episode, Dave declared to Phoebe that they were going to go after Nick this time (not Rio). Beth was hesitating all episode about actually running for city council, and intersplicing her change of heart with her discovery that Nick was in fact lying about his involvement with Rio's business indicates to me that Beth intends to help the Secret Service go after Nick, and she's running for Council to get close to him and therefore to get dirt on him. She then rejected his offer to drink, further emphasizing she has no real intention to bond or get close with him—or romantic interest in him.

I was talking about it with @riosnecktattoo this morning, but I think he really doesn’t know and I think that’s part of the reason he’s spinning out so much. This is something he’s on the outside of, something that’s taking place beneath his radar, and as much as he wants to know, he both can’t ask because it reveals his hand (he’s been playing it up to Nick that what he and Beth have isn’t meaningful to him—and god, it’s so delicious that this tactic might have specifically been Rio responding to Nick’s tendency to take what’s his, only to create the circumstances where Nick transparently seeks to do just that) and because he doesn’t want to ask because the truth might be terrible, and once he knows it, he can’t unknow it.

I’d say he thinks there’s been a development in Beth and Nick’s personal relationship that may have crossed over into romantic, and he’s definitely entertaining the possibility that something sexual happened. Nick hasn’t been shy about pursuing Beth in that regard (“lovers’ spat” and “I was making progress” and “that’s not my style, brother”) as part of whatever his overarching plan is with her, and by gifting Rio a bottle of liquor as a “thank you,” it definitely has celebratory connotations that are suggestive that it’s not merely about getting her to pursue the political campaign—particularly because of the sexual connotation of "yanking her by the ponytail."

The bar scene with Rio and Nick is so wonderful because it’s all bravado and male ego—Rio reduces what he has with Beth and oversimplifies it in a way that is frankly an outright lie. He says Beth isn’t the the type to be romanced, she’s the type to want her ponytail yanked, but he knows that their most honest moments of intimacy followed after softer moments where they connected with each other and he saw her—her potential in 2.04 and her pain in 2.09. He also knows that he’s let her take the lead and initiate all sexual scenarios, yet he boasts that he’d “give her what she needs,” like that’s how he would motivate and sway her? No, it isn’t! 4.06 is murky, but it’s also genuine, and it’s also not something he pursued as much as responded to—yet he reframes things to give Nick bad advice. Yes, Beth responds to and even likes getting her ponytail yanked by Rio, but only because it’s paired with and part of their dynamic where he responds to what she really wants, which is to be seen and respected—something he gives her, in his own twisted way, when he shows up to Sweet P’s and forces her hand, but not without telling her that she’s capable of pulling it off because she did it with Boland Motors and Boland Bubbles (which—despite how they imploded—were successfully run businesses although she was inexperienced).

Rio basically gives Nick half-accurate advice based solely on his professional relationship with Beth, but makes it sound like it’s the personal part of their relationship, all while pretending he doesn’t much care for it. Then we get the “pour it out” scene, which adds this whole other layer to their dynamic. @pynkhues has written about it before, but the show is really careful in how it portrays Rio as a boss versus a lover, and this scene fits neatly into those distinct boxes. Rio is possessive and controlling professionally, and that may even be motivated personally (his self-insertion into Sweet P’s being a prime example of that), but when it comes to the purely personal part of their relationship, Rio is much more generous and soft. I love the decision to show Rio’s jealousy at the potential between Beth and Nick as something that tears him up rather than something that makes him explode or act out. Rio often masks his feelings into anger or irritation (his fear for her in 2.07, for instance) but here, privately, at his most raw and vulnerable and honest, he’s simply sad. There’s not possessive outrage at the transgression, no vindictiveness or denial of the feelings by, say, pursuing a retaliatory hookup to prove he’s not affected. He just feels loss.

It's a sexual innuendo!

RIO: Maybe she's just not that into you, bro. [Rio positions Beth's disinterest in the city council job as Beth's disinterest in Nick romantically/sexually]

NICK: Mm, she'll come around. [This line probably means that Nick thinks she'll ultimately run for office, but could also imply he thinks the chances of a hookup aren't quashed yet, either]

RIO: Chicks like that don't need to be romanced. [Rio's advice is that Nick doesn't need to take his time and woo her to get what he wants from her—they may be talking about the City Council role, but Rio is determined to keep the conversation rooted in romantic/sexual terms]

NICK: Oh yeah? What does she need? [Nick takes the bait, but has an edge in his voice that suggests he's not entirely buying into Rio's schtick here]

RIO: Someone to yank her by that ponytail. [Coming off of Rio's previous line, this implies that instead of being wooed through traditional methods—like gifts or compliments—she needs someone to dominate her and force her hand, that she likes responding to power plays. Hair pulling is often associated with rougher forms of sex, so Rio is suggesting Nick needs to more forcibly guide her, but he is also implying what type of sexual relationship he and Beth have had—which is partially, but not completely, true.]

NICK: That's not my style, brother. [Nick rejects the idea of dominating Beth in this way—as we know, he prefers more subtle manipulation and underhanded moves. This line makes me think that Rio already knows this about Nick, meaning that Rio is deliberately positioning Beth as someone incompatible with Nick and undermining Nick as being capable of giving Beth what she "needs"—professionally and sexually]

RIO: You want her in that seat, right? [Here, Rio pulls back to the actual conversation at hand in straightforward terms. He's using sexual metaphors and using them deliberately, but the main issue is getting Beth to run for city council.]

NICK: What would you do? [Nick seems to hesitate and cave, allowing that Rio may have worthwhile advice; it's interesting that he only really does this after Rio speaks in plain terms.]

RIO: I'd give her what she needs. [Rio has already laid out that Beth "needs" someone to yank her by that ponytail, meaning that he would force her hand. But he says it smugly, and the double-meaning is supposed to be evident: he's suggesting that he would sleep with her, and that it would be rougher sex where Rio was dominate/in control while Beth was submissive. This line is all about ego, making Rio come off as having sexual prowess that Nick has already established in the scene that he doesn't have when he balked that that wasn't his "style." It's a misrepresentation of his sexual relationship with Beth as it does not include or account for how intimate and soft their sexual encounters have been—or that Beth exclusively initiates them]

Throughout the conversation, they're talking about Beth running for City Council, but Rio makes sure to frame everything in sexual terms that establish three main things:

Beth is disinterested in Nick,

Rio is leagues ahead in knowing and understanding Beth,

Beth and Nick are incompatible in ways that Rio and Beth are not

as much as she hates it, she loves it, because it means he believes in her and she responds to that.

I love that it seems it both is and isn't a copy of Rio's MO?

Rio giving Beth the bottle of bourbon was, after all, a signifier of and reminder that he knew her—a key element in Beth finally letting down her walls and choosing to seduce him. In contrast, when giving the bottle to Nick, Beth specifically says, "Well, I figure [emphasis mine] it's what fancy politicians drink." It's an assumption and therefore a rather impersonal, generic gift based on her own interests rather than Nick's.

Like, Rio, though, Beth offers the bottle as somewhat of a consolation prize in a larger game that's being played, specifically one where she's using Nick as her fall guy like Rio was using Beth in season 2 by putting the storage locker (and everything else) in her name.

Both Beth and Rio have conflicting, personal motivations in these moves to pull the other person closer—the difference is that Rio's came from real feelings that he was developing for her, while Beth's come from a desire to take Nick down, which came from her feeling betrayed by his lie about not getting involved or being able to pull strings when she thought her sister was in danger.

anon, the thought of rio thinking beth initiated is fucking me right up. but after my initial spiral into madness, i think i want to say that if he had to guess or think about it (which i think he is Desperate not to do in too much detail, even though i also think he Cannot Help Himself), rio would bet on nick initiating, mostly bc nick is so openly pursuing beth in their conversations.

plus, rio has never really tried to initiate (i am literally obsessed with the fact that his most overt flirting always occurs when he absolutely knows she's going to say no, namely when he suggests a bathroom break in front of her friends and when he propositions her during a hostile business meeting) and he knows exactly how difficult it was to get beth to initiate, how much build-up there had to be, how everything had to fall into the exact right place at the exact right time.

adkfa;kdf i know, it's so good, and i feel like 4.13 was really in conversation with it? like, rio leaves the dubby in the mailbox because he can't handle being confronted with what it means that he retrieved the dubby, and then beth drinks the bourbon he left for her at the end of 2.04—and then you have this final scene where rio stares at the bottle of bourbon that's indirectly from beth, but he doesn't know it, and really, it's a symbol of rio winning because nick can't pin beth down (whereas the previous bottle was a consolation in exchange for beth losing/rio taking the money because rio knows beth).

unlike 2.07, in 4.13, rio doesn't get the option not to confront how he feels. where beth has to drink just to be able to open the envelope because she knows what's inside but she still finds it shocking, rio can't drink because he's so consumed with the idea that something has happened between nick and beth, and it just crushes him in a way that leaves him no option but to feel every painful aspect of that reality.

in both instances, a gift reveals the truth, but in really different ways, and i love how they really showcase the way that rio's feelings for beth have only deepened in a way that rio still finds completely overwhelming.