I doubt this. It is just bodybuilding, which is often considered a narcissistic pursuit. When the focus is on our physical selves, some people will seek appreciation and reassurance indiscriminately. Many women are not impressed with a guy's muscularity, especially when it involves a lot of primping. We're humans, not peacocks. If we were, fanning our feathers would impress the ladies. Also, for most folks professional bodybuilding is not all that lucrative. In order for the average person to maintain the expense pro-bodybuilding entails, they may resort to prostituting themselves one way or another. Many proclaim they are straight regardless of what they are willing to do for money. I'm not at all sure this makes sense. Some people have delusions.
Having said the above, I do believe bodybuilding attracts a lot of interest from gay men. I'm not sure gay women could give a shit.
There is probably more homosexual behavior going on in contact sports than most folks realize. Locker room shenanigans are not uncommon with athletes. Hazing sometimes includes homosexual behavior, which is thinly disguised as guy's just being guys.