Advice please

My boyfriend who is 16 and I'm 15 almost 16 we have been together for almost 9 months and idk I get jealous easily and he stayed over a girls house all night with a few of his friends I hate this girl i don't like him hanging out with her but I haven't told him but he knows I get jealous whenever he texts her and idk what to do am I over reacting because people who were there say nothing happens and they don't talk or do anything but I'm still jealous idk what to do I love him he was my first everything first time (ik I'm young but I didn't want it to be anyone else) first kiss first date first real relationship I trust him but I don't trust any other girl around him because I'm afraid that they are going to do something but idk am I over reacting or what should I do