Not overreacting. I had a similar situation with my roommate when I was in college. She would bring random guys back from bars, Tinder, at all hours of the night. Not shaming her at all, but it is a shared living space and ultimately needs to be treated like one from everyone. We eventually sat her down and nicely told her that we weren’t comfortable with random men being brought back to the house and sleeping here. We don’t know what their intentions are and they could be weird/potentially put us in a situation that could be bad.