My son wants to get laid

[Big Bend]

My oldest son is 16, and is "in love" for the first time with a serious girlfriend. She's also 16, this is her first boyfriend. They are good kids, get good grades, I couldn't be prouder. But several times when she has come over to visit we've said "keep the doors open" only to find them closed at some point. Her parents have the same rule when he goes to visit at her house. Neither one has a drivers license yet (tho my son will be getting his in a few months).

My wife and I are pretty liberal, and fully expect/hope he'll make good decisions and be responsible when the time comes for him to "grow up" so to speak.. but obviously he is wanting more from this relationship now, and is feeling very "controlled" and frustrated. I told him look, when the girl's parents say its OK then we'll talk, in the mean time quit trying to make out in our house.

Any suggestions/advice on how to proceed much appreciated.

thx.. BB