Interesting headcanon but I have to disagree with the puritanist stuff, Cait is canonically the character who used sex as coping mechanism after the breakup and her shyness in the brothel was regarding never having been in such type of environment, as soon she is put in a situation she needed to flirt she handled that as natural, giving background that she isn't shy to sex or making advances at all.
hello! Yeah, i can see where youre coming from. This is another way to interpert the brothel scene, that i see quite often. The thing is- we don't actually see Caitlyn flirting. She does look much more confident in that scene, which i think can also be ascribed to her using her deductive skills- Caitlyn's always shown to be really confident when practicing shooting or detecting. She looks interested (the point of the scene is to sell the idea that Caitlyn is into women), but based on what the masked woman is saying, it looks like Caitlyn asked her about her aspirations- not really forward with the sexual stuff. it reads more like traditional courting to me, which is what I assume Piltover's dating culture is closest to. Which is very different than what this lady, who works in a brothel in Zaun, is probably used to, and so she is very charmed by Cait. I doubt anyone ever asked her about something so sweetly personal before.
What im saying is- i dont think Caitlyn stepped offscreen and started outright flirting with another woman, not in the direct sense we saw Vi use on her moments earlier. What is most likely to me is that she decided to mimick Vi in a way she saw appropriate- and approached a woman working there, courting her the way that she would in Piltover. Which is much less sexual and raw, and more formal (think old timey english novels). Caitlyn looks so flustered in the brothel not because she's not used to be the one *courted*, but because that open and raw way Zaunites flirt is something she had never experienced before.
As for Caitlyn using sex as a coping mechanism- that's another interpertion that's relatively common, and im not 100% behind. i dont think that after Vi left, Caitlyn was so honry and needed a sexual outlet that she actively chose to court another woman. is this something some characters do? Yes. Has Cait been established as a character that turns to sex for relief before? No. We again don't see how Cait and Maddie came to be- importantly, we never see Caitlyn pay any attention to Maddie prior to the scene with her in her bed. In all of Caitlyn and Maddie's scenes, Caitlyn is closed off and turned away, her head is somewhere else entirely. If they wanted to emphasize that Cait needed Maddie purely as a physical, sexual outlet, wouldnt it be smart to show Caitlyn actively pursuing her? Maybe show Caitlyn hungrily fuck Maddie, and then see her close off after? Anything at all would push this to be the more accurate reading to me. Caitlyn doesnt look like she's attracted to Maddie even in a shallow physical way. Lowkey she looks semi turned off by her. Maddie doesnt even get a confident heated look like we saw in the brothel. So if that's the angle they were going for, they failed to communicate it.
However, based on what we did get, it seems more likely to me that Maddie, a mole who's been put there to spy for Ambessa since day 1, needed a fast way to get closer to Cait. after she saw Vi has left, she rightfully assumed that Caitlyn would be very vulnerable, and seized the opportunity. Im almost 100% certain that Maddie is the reason this little affair happened at all. As for Cait, the reason she accepted Maddie's advances wasnt for sexual relief, but an emotional one. She just lost the only person in her life she felt intimately close to, and she is notiriously hard to open up. Her father is barely present, her mother is dead, Jayce has dissappeared. Caitlyn had no one, and this little seemingly innocent ginger comes in her sad world and fangirls all over her. Her loneliness makes her much more likely to cave in if Maddie pushes, and i assume a part of her thinks it'll take her mind off Vi (lmao she really thought).
And last thing. I dont think Caitlyn is a puritan. She doesnt find sex gross or anything, and she clearly experienced it before Vi (and Maddie). I just think she was raised to pursue it in a very specific and formal way, and her affairs probably werent very exciting. That's why Vi's brashness always catches her off guard, but she is clearly attracted to it. She's not a shy, twirling her hair, innocent girl who doesnt know how to handle sex. The best way to explain is as id and ego, the id is the primal sexual needs she has and the ego is her overthinking brain, who thinks she can rationalize herself out of her own needs. Vi represents that id for her, and lets her go loose. I hope that explained it.