ahh I am honored you trusted me with this lol I'm always dying to dig into these kinds of questions!! I'll start with Matt, whom I honestly do not think has sexual feelings or designs towards anyone or anything that he is really aware of, but I do think he tried performing those kinds of feelings more when he was younger. he wanted a girlfriend on his birthday that year in webseries, but he notably never said anything about wanting something sexual to go along with that. and, actually, when faced with the possibility that he could have something sexual (the lap dance) he is completely horrified and says "I'm not into this, I'm not into this" repeatedly while backing away. After it's all said and done, he comes to the conclusion at the end of the episode that he is entirely fulfilled by the act of having a best friend (a nonsexual form of intimacy). This episode is basically the last time we ever hear Matt ever express interest in having a girlfriend or even really talking to women with that kind of intention. I would go as far as to say that not only is Matt not sexually interested in women, he is not really explicitly interested in sex at all, with anyone. But that's an entirely different and new can of worms to open and not really what you asked so I'm going to try to stay on topic LOL.

Okay now on to Jay who I think is less straightforward than Matt in this way. Unlike Matt, we know that Jay has had sex with women, Jay likes attention from women, Jay is interested in women explicitly and especially early on but we still see shadows of that in the viceland era and even in the movie when Matt is talking about girls wanting to take pictures with him as you mentioned as well. I think one of THE defining features of Jay's character to me is his intense vanity. Jay likes approval, Jay especially likes approval from girls because it's a kind of approval that helps solidify him as a normal guy in his own mind. When we see Jay flirting with women it's almost always juxtaposed next to Matt's weird bizarro behavior (autumn leaves, peanuts, etc). I think Jay feeds off of this contrast, he revels in the feeling that even though, sure, Matt might be a bit of a freak, Jay can still be a cool, regular guy. He still gets that seal of approval from women, he's still desirable to women in a way that has never been attainable to Matt. Jay gets off on feeling like he is better than Matt, and he also likes reminding Matt that this is the case esp with women. Matt and Jay are both raging misogynists but in different ways. Jay absolutely sees women as objects and prizes that he can use to reinforce his particular model of masculinity (sensitive musician artist type) and also trophies that he can use to validate his feelings of superiority over Matt. Whereas with Matt I think he tends to feel very misunderstood and rejected by women overall and therefore just kind of learned to discount them and their personhood altogether in some desperate attempt to save himself from their judgement (both are bad obviously). But it is so key to my characterization of Jay that he needs to feel superior to Matt in order to justify his continued relationship with him. If he sees himself on the same level as Matt he would have to admit that he is just as anti-social and socially unacceptable as he is and that is just not something Jay feels willing to do. I think a lot of close relationships between men hinge on this kind of dichotomy.

As far as whether or not Jay actually, apart from Matt, wants to have sex with women by the later eras, viceland and the film, I honestly think by that point his desires are so inextricably tied to Matt that it almost doesn't even make sense to try to evaluate them on their own without factoring in the way he wants to prove that he's more of a ladies man or whatever than Matt or to emasculate Matt. It's very important to remember that the one longer term sexual relationship Jay had was with Matt's sister LOL who in the end was thrown to the wayside by Jay so he could pursue the band and further his life with Matt. We do see Jay kind of regretting this decision in the webseries but by the viceland era it seems completely eradicated from both of their memories, a distant relic of a past that is now irrelevant. In a lot of ways that decision was a symbolic one to me - Jay knows that Matt isn't interested in pursuing those kinds of relationships. Jay knows Matt is VERY uncomfortable with him pursuing them as well - sex functions as an existential threat to their domestic life together. It's something Jay was willing to forego in order to keep his life together with Matt in tact. It's so interesting to me.

I will say too, that little moment in the film where Matt mentions how the girls will want pictures with Jay was very sweet and endearing to me. I don't think Jay cared at all about the girls wanting him in that moment, I think he was so much more invested in the fact that Matt was intentionally trying to butter him up and stroke his ego and compliment him for being good looking than he was in the possibility of actually hooking up with any of the fantasy women wanting those pictures with him. It's relevant also, imo, that even as famous Jay, we don't ever see him hooking up with models or pursuing women's attention outside of friendly meet and greet types of settings and taking pictures. A lot of films would have had their suddenly famous and undeniably handsome male lead immediately enjoying the company of all the most beautiful women in various ways. That is not what happens in their movie lol. And really we NEVER hear "sex with women" or even "dates with hot women" as a motivating factor in pursuing the success of their band, not really even once in the whole series does that ever come up. The motivating factor is always some amorphous goal of fame and playing the Rivoli together. I can't think of a single other show about guys in a struggling band that has never utilized hookups or relationships with hot women as a motivation to hit the big time, yet another thing that makes nirvanna the band so unique.