Most Helpful Girl
It's simple: Get over it and move forward.
You really just have to accept that for whatever reason, that person does not want you as a romantic or sexual candidate. Don't get too in your head about why. It may not even be about you but about the fact that there's already someone else who has their eyes... or their heart... an ex perhaps... the one who got away... you never know. Journeys are complex things! <3
They don't want you. You can't have them. Get over it. I know it sounds harsh but the quicker you accept it, the sooner your jealousy will fade.
You're at a party, have fun, dance, socialize, she's not the last pretty, worthwhile girl in the world.
Most Helpful Guy
boost yer confidence maybe?