What do you think?

my girlfriend wants to ask another guy to the sadies dance. i dont go to her school and cannot go because outsiders are not allowed for 9th and 10th graders. what makes it worse is the kid she wants to take is a kid who likes her and someone she supposedly "used" to like as well. she says they would go just as friends, and that she shouldnt have to suffer because im in another school (actually cyberschooled) but i feel that if it were me id rather stay home and be with her than go to a dance with another girl.