My boyfriend took another girl to a basketball game

Lulu

So long story short, my boyfriend and I are long distance. He had bought tickets to a basketball game for him and his friend but his friend ended up not being able to go. Instead he decided to take a girl, that he dated before me and now claims that they are “really good friends”, to the basketball game. When he told me he was going to take her, i got very upset because i felt uncomfortable with how much time they would spend together alone. A couple weeks ago he told me how she was sleeping with some guy, while she was STILL dating her long distance boyfriend. So more reasons to be concerned with them being alone. I’ve met her before and honestly, I didn’t get the best vibes from her. He knew how upset I was and how i felt about this situation and he still took her. I am sooooo mad and i don’t even know how to get over this. He can have friends that are girls, I don’t care. But it just really bothers me that he had other guy friends to take to the game BUT STILL CHOSE HER!!!! Should I just build a bridge and get over it or what??