A Little Upset

So, tonight my friend Amanda gives me a call and tells me that some of our friends are going to be at the fraternity house to just hang out and have some fun. So, i decided to go seeing as i wasn't at all sleepy (at 12:30am) and i haven't hung out with some of the boys in quite a while. I was really happy when i entered the house because it was kind of like old times: the boys, Amanda, the brothers, just chillin and having a great time. Then, i noticed Steve's ex was there, which was fine with me because i actually respect her as a person, seeing as she hasn't given me a reason not to. So, i went on like it was nothing and proceeded to chat with some of the boys. Then, i see one of the brothers walk up to me and i think, "Oh Shit". Yup, i knew what was coming: i had to leave the house because Steve's ex was there. I wasn't even there for five minutes, barely enough time to greet everyone and then say goodbye. It was actually quite embarrassing for me to have to show up and then suddenly leave without an explanation. What upsets me the most is that, as long as Steve's ex is at one of the fraternity kickbacks or parties (and she is friends with the majority of the brothers, so she has every right to be there) i can't go. That actually pisses me off because a lot of these boys are like my brothers, and i love every one of them. It just seems so damn childish. Steve and his ex broke up about three months ago and i still am not allowed to be anywhere she is. I mean, aren't we all adults here? Can't we act like it? I would never tell her that she wasn't allowed somewhere where i was (even at my own house) if she shared mutual friends. It just seems so unfair (yes, i know, life isn't fair). I was so excited to go hang out with all of the boys that i have missed so much but i was forced to leave so soon. Doesn't anyone else think this scenario is just rediculous? Or is it just me?