Hotel for prom

So I’m about to turn 18 and I wanna get a hotel with my friends and boyfriend for prom. We don’t wanna go to dangerous after parties so we wanna get this expensive hotel so we can just have fun with a couple friends. The hotel we’re getting is like a mini apartment with several rooms and I’m trying to convince my parents to let me go. To tell the truth all I’ve ever wanted was a night alone with my boyfriend because I can never have a minute alone with him, my parents are always breathing down my throat when he’s at my house. I hate lying to my parents about his whereabouts but I just wanna have fun with my friends without having to worry about getting caught. I’m on the pill and we use condoms all the time. If I could use the fact that I’ll be 18 at the time, I would but I’m going on their money and living in their house. I really don’t know what to do.