AITA. My partner (20F) is telling me (20M) that I’m not allowed to attend swimming events without her presence if there are other girls present

With summer coming around the corner I’ve been wanting and thinking of some ideas for local trips to make that involve swimming; Going to our local waterpark, boating on our nearby lake, attending pool party’s, e.t.c. But out of the blue when talking about this she told me that I’m not allowed to be around the opposite sex without her being there cause it’s “being loyal” and our right told me “this is not about trust issues”. She also said she would refrain from doing the same thing, but I told her that I trust you and know you’re loyal to me so don’t force yourself to do that, and I wouldn’t force you to be in my presence when you’re around shirtless guys. Am I the asshole for suggesting that I can handle myself in front of the opposite sex in skimpy clothes, or do I need to “be a man”?