A favorite scenario-
My wife does prefer MFM over MFMF wife swapping. Probably because I'm there with my attention on her even if she's one on one with the other male. She can concentrate on the other male while I... keep track of the action. And she's confessed, "If I can get you and the other guy to cum, I've done my job".
She does gage her desirability and attractiveness by her sexual performance. If she can get a guy hard just by kissing him, that's huge for her. If she can get a guy to cum by how she fucks with him, that's the ultimate. He couldn't cum if he wasn't aroused. So filming her as a guy pulls out of her pussy and gives her the money shot is her proof that she has that sexy allure about her. I'm excited to see it happen because she looks forward to it. The guy does put his dick back in her so I know she took some of that cum. I follow up right behind the guy. My wife spreads, her pussy loose and already lubed. I do tell her she needs to be "reclaimed" by her husband. And then my dick goes in her.