Don't get me wrong, both girls are pretty, but watching girls (or anyone, really) make out just doesn't do anything for me. Maybe it's just because I don't find it all that taboo; I dunno.
I just know that scene starts to drag in the context of the movie. It might have made more sense if they had implied that Needy had been attracted to Jennifer up until that point. As it was, it felt sort of shoehorned in to get some guys to see the movie and ensure a "Best Kiss" nomination at the next MTV Movie Awards.