Strict parents

I’m 21, in school and live with my parents. My boyfriend goes to school out of town and every time he visits he’ll get a hotel room but my mom will not let me go to his hotel room! I just want to have alone time that doesn’t involve sitting in a car. Any tips on what I should say to my mom? I’ve tried to tell her that she won’t be able to chaperone my decisions forever and I need to make my own decisions, even if they’re wrong but that didn’t work.