My boyfriend and I want to spend the night together while he's in town....but in our homes with our parents.

My boyfriend and I, 18 and 17, want to spend the night together while he's back in town for a few days from college. We haven't seen each other for two months, so it'd be very, very nice to have a real night together.We are absolutely serious with each other, and we do understand that we are young, but we're just winging it as each other's first boyfriend. So spending the night together is something that we both want to do without regards to sex.The problem is that we aren't sure how our parents will initially feel about it. Mine are very liberal and accepting about our relationship and approve of it; they are perfectly fine that we would want to live together after I graduate, but they wouldn't usually allow us to be at home alone.His parents are more conservative, but we don't know how they might take it since he's in college and he has more freedom.How can we try to convince them to let us spend the night together?