Eh, I disagree. I don't think it's about obligation, more like, what reason do you have to turn her down? You're already acquaintances, and you're gonna blow the time eating shit anyways, what harm is there? It would be one thing if he hated her but clearly that's not the case, he's just socially awkward especially around women and he's kinda a dick in general. He did end up going with her anyways lmao.
what reason do you have to turn her down?
to want to be alone? to not want to deal with the social anxiety that comes with spending time with a woman? there is actually a lot of mental anguish involved for someone like him.
and I mean yeah for the sake of the story and plot moving forward, they had him go with her.
his initial plan was to break this thing off on the first date. then he didn't even want to pretend to go on a date, he just wanted to give her the tickets and then he'd dip. For the sake of the plot, she forces him to go with her. That's 2 occasions where he's shown he wants nothing to do with her. After the movie, he's fine with going off on his own. The plan was never to spend time with her. Yet again, she keeps insisting despite him showing and telling her he wants to be done with her.
Even if you don't hate someone, that doesn't mean you have to hang out with them. One doesn't even need a "reason" to decline someone's invitation. If they don't want to go with you, they don't want to go with you. It's really that simple.
This chick is just literally dragging the plot forward. People are right to question her motives because this isn't realistic as it is. If someone has shown more than once that they don’t want to hang out, why would you insist and force them to?