Marital sex just needs to be varied. If the couple won't do it together, then clearly they will still do it secretly each separately! I think this home variation is acceptable, in any case it is not as extraordinary as entertaining a large group of swingers. My wife and I once invited me to one of these, against her this clip is just sex puritanical family!
Just the girlfriends had lesbian sex and then such a buzzkill man interrupted all the raspberries and showed up. It was bad luck to catch the girls at the most interesting moment, it happens. Although on the other hand the man then rehabilitated himself in the eyes of one and the sex continued, and for the one who left he remained a buzzkill. He was a good shot, of course, he gave such force with his sperm near his eye that he would have been left without an eye.