My girlfriend and I are both 19, dating a year and a half, and she is in a sorority at a different college than me. She has a date party coming up and I can’t go because of school. She wants to take a guy who she is friends with. Should I be okay with this because honestly I don’t feel okay with it. She has plenty of friends going as a group so I don’t like the idea of her going with another guy. Any advice?