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!
In fact, it's a proven fact. No one would refuse such a training session on boxing, see how she was furiously sucking his big dick, and she seems to be enjoying it as well. In general I think that such a fuck will be a norm for them now, because they are unlikely to stop at the received emotions, they will want more and more, and there more and more, we just have to watch.