The lines of sexuality are getting blurrier than a motha these days! There are clearly many levels to this lifestyle and everyone has to decide what level is best for them to participate on. It's not for me to define another man's sexuality but it is for me to define my own. When I get contacted by bisexual couples and offer's are made for another man to have some form of sexual contact with me I respectfully decline and wish them all the fun they can handle in the lifestyle. I don't get angry. I don't get offended because actually my swinger profile says that I am straight. I just politely let them know that is not my thing. Very few of those couples have decided to proceed in inviting me for a threesome anyway but some did compromise on the male to male contact and I played with the wife and the cuck cleaned her up.
I personally only had a few encounters with bisexual couples where the cuck ate his wife afterwards because they almost always asked for more male contact like a blowing the bull and they refused to compromise and go forward with playing if the bull was unwilling to have even one way contact.
I personally don't think it's widespread though you could clearly see the increased demand for bisexual bulls by more and more bisexual couples popping up on Craigslist.
I think if you took a poll and asked bulls: how many bulls would allow the cuck to suck him, or simply just allow the cuck to eat his cum out of his wife and lick it off her too? Most bulls would say that he can do whatever he wants with the cum once it's in or on his wife! I doubt that most bulls will allow a man to blow them! But I am curious to see what the results would be on this site?