First of all, how each one of cuck, hotwife and bull should dress and behave must be discussed and agreed upon by all the three before starting the lifestyle. There should no disagreement on any issue among the three and all three should be comfortable on what is happening during the session
Personally, I would prefer cuck to wear only bra and panty when I am pleasuring his hotwife. When cuck is wearing bra and panty, it is an assurance to the bull that the manly role has to be performed by the bull only and the cuck has agreed to surrender that role. Additionally, I would prefer cuck not to cum until our session is over. If cuck is unable to control his orgasm, he should lock himself in chastity. I would expect cuck to serve us during the session with water, snacks etc. I hate bi stuff. However, if the cuck is willing, he may cleanup his hotwife once our session is over.