Nerdy girl is convinced to go on a date with a guy (if I remember correctly she’s never been into having a boyfriend). They meet up at a bar, and she’s very skeptical at first, but the more they talk the more she’s falling for him- As they share a lot of the same interests (a specific book if I’m not mistaken)

But turns out this guy has not been honest with her, one night at his apartment when they are about to make love, his real girlfriend is walking in. And the nerdy girl buttons up her shirt and storms out.

Thats all I remember. Hope it’s enough for any of you to remember. But I’m pretty sure movie is not that old