Quiet as it's kept, I don't believe there are as many 100% straight guys as we have been lead to believe. I think most of them have had some same sex curiosity even if they never act upon it. I also feel a lot of them would be fluid if they weren't so afraid of the labels society places on men who admit some same sex interests. It's impossible to even estimate since men are far less likely to admit same sex attraction than women are.
It's really too easy these days for them to satisfy same sex curiosities via porn vs actually having physical, sexual contact with another male. Trust, there are plenty of "straight" guys who have watched gay male porn and developed full blown erections but have never physically had sex with another man so they consider themselves 100% straight. I've heard "straight" guys joke about things like tops, bottoms, verse, grinder and I'm like, wait, if you are straight, how would you have any knowledge on those subject matters??I've been gay all my life and I just found out what grinder was about 5 years ago.