That's assuming there even was any cheating.
If your sole source for that assertion is Nick and/or April, I wipe my ass with that. They have zero credibility. Nick is a pathological liar, and she is a dumbass under his control.
(Note that for the purposes of this discussion I don't consider swinging to be cheating, given that they all seemingly consented).
Look, my issue with Kayla is the same issue with all the rest of them. They all willingly participated in this crap. I don't know who started what, and I'm not sure it even matters. If it were to be confirmed at some later date that Kayla pushed for this, I don't think Nick looks much better, if at all. He should have said no.
It does seem that's the case, yes.