True Heterosexual Alpha Bulls DO NOT ENGAGE IN MALE TO MALE CONTACT!!! Gay and bisexual Bulls let the hubby fluff and clean them, but not a STRAIGHT Bull such as myself.
Maybe so, but the only times I've ever been told to "get a bull ready" for my wife with my mouth or hands, or clean up after he came on her, it was at the instruction of the bull. Every bull we've ever been with has listed himself as straight, and we've never felt a need to correct the ones who stuck their cocks in my mouth. I don't know what the actual statistics are, but in our experience it's been about 50/50 whether a bull is into things like having me fluff him, stroke him, guide him into my wife, clean up after him, etc. We're always discreet about it, and I've never instigated any play between me and a bull.
If a man is masculine, dominant enough to take the lead with her, but respectful enough to make her comfortable, and sees any contact with me as a roleplay/power thing, that works just fine for us. You can decide whether they're straight and into dominance and submission, or closet bisexuals making excuses, but that distinction has never been important to us or given one man more "authenticity" than another. Of the men we've played with, those you might say are making excuses all gave my wife AWESOME sexual experiences, they definitely put their money where their mouths are (and then some) in terms of cock size, physique, stamina, and fun play, and they get plenty of action in their local scenes, so I bet they don't care whether the peanut gallery in online forums consider them "true heterosexual alpha bulls" or not. To hotwives in the lifestyle, they're model alpha bulls, and they get plenty of what they're looking for.
My wife usually asks ahead of time how a bull feels about my participation in various capacities, if he doesn't bring it up first. Responses range from me not being present at all, to just watching, to just having contact with her, to having contact with both. Her preference is bulls who are open to at least my being present and having contact with her, if not both. Her top priority is having great sex for her, which is something that turns us both on, but she definitely enjoys driving me crazy with jealousy and making me feel submissive, which is more fun with me physically present and involved. She's more than cool with the answer, "hubby can be there, but having him touch me isn't my thing," and "I want you all to myself sometimes." She's even had a couple playmates who ONLY wanted to be with her alone, without involving me at all, but those tend not to become ongoing things. She gravitates toward fun, open-minded men who actually enjoy the dynamic of a married woman who's a lady in the streets but a freak in the sheets, and cuckolds her submissive husband, rather than those who put up with her married status just to get laid. She doesn't care how bi or straight others would consider her bulls, as long as she finds them attractive, they enjoy playing their part in our situation, and they're good at what they do. Outside of that, straight/bi labels don't serve much use to us.