I remember this movie scene where a couple, I think they’re childhood friends, are hiding their new relationship from their families. They go home for maybe the holidays and are staying over at the girl’s parents house. I remember the guy sneaking in to her room during the night in nothing but a dressing gown as apparently she gave him some sort or ‘signal’ earlier for sex. They end up talking in bed and then she opens up his dressing gown saying ‘oops’ in order to initiate sex. I also remember the mother outside basically knowing what’s going on.