I'm currently putting together an episode focusing primarily on clean up... Tell me why this turns you on so much.
This might be a bit late for the particular episode, but here are my thoughts as a cuckold husband on the subject of "clean up".
Gently cleaning up my wife's pussy as her Bull's cum slowly drips out of it is the ultimate form of submission, arousal, humiliation for me.
Humiliation:
My wife doesn't let all of her Bulls fuck her without a condom (heck, most of the time I don't get to fuck her without one), and so the few Bulls that do get that honour, she holds in very high regard. And this is one of the first aspects of the humiliation for me - only the Bulls that she really is attracted to, has a strong chemistry with, and that she has insane sex with, get to fuck her without a condom. And so, there is this element of great humiliation that the Bulls that do get to cum inside her are really special and superior men that she has chosen to cum inside her.
Arousal:
Watching my wife being properly fucked is one of the most arousing aspects of the lifestyle for me. Hearing her moan, and scream, and shake in orgasm, drive me wild. Hearing her beg for her Bull to cum inside her, and then hearing her tell her Bull how she can feel every shot of his sperm, was so arousing that I accidentally came once. Part of the arousal also comes from the humiliation knowing that this Bull can clearly fuck her much better than I ever could.
Submission:
The greatest aspect of the "clean up" that I enjoy is that it is a pure form of submission. The cuckold handing over any control he thought he may have had, to his wife and her Bull. They make the decision to forgo the condom and they make the decision to let the Bull cum inside her, and all the cuckold can do is accept it, watch (if I'm lucky), and then clean up. The act of being called over to lap up the Bull's cum as it slowly drips out of her is also the ultimate form of submission in my mind.