Advice

Next week I'm trying to go with my friend, her SO and my SO we were thinking of going to the movies. The plan was my friend gets fingered by her SO while me and my SO have sex again. I know there is this other place, the Water Tower has a Macy's that no one goes in to. The only reason I don't want to do it at one of our houses is because there's a chance we might be caught. We're both 18 but that's something I don't want to happen.

It would happen in the changing room since it's the most private spot. What I want to know is how would you do it? Like if you met someone and took them to a changing room to try to have sex how would you go about it