Hmmm, it should be that during your first encounter, you don't get any choice to pick costume first. So, you didn't get any scene when you were going on a night date for the first time? (did they go to Toru's room or hotel room?)
Maybe I'm mixing memories, but surely the first time it was at Toru's house, where their parents were gone, they talked about putting the book to practice and so they did... It went to foreplay tutorial, let me remove all his clothes, and then do it with Toru all the way, then slept until morning... But no mother interruption in any moment.