First-time overnight guests at your girlfriend's parents' house are always awkward. It usually involves early jogs, "including" yourself, and sleepless nights. Pamela's parents made it very apparent that you were to remain in different rooms when you arrived. Even though it has been a week since you two arrived and you haven't really interacted, Mr. and Mrs. Morrison went to bed early tonight. It seems to me like a window of opportunity. Keep a tight lid on yourself because you're doomed if Pamela's parents wake up and she crawls onto your bed to start sucking your cock and mounting you.