This is great because it shows the "reality" of the process of swinging. While very erotic, there are definitely things that can happen that can lead to insecurity, so you have to establish "ground rules" and this clip let us see a little part of that.
Yeah nothing's as hot and sexy as mid-threesome rule enforcement :P
Notice the guy walks off after that. That's the right move.
Is it her husband who wants that? Dude, you're filming your wife gobbling another dude's cock...you're not saving any dignity by enforcing some petty restriction, you're a cuck