Bisexuality differs with many levels of interest. With 94% of us being bisexual at some level, it varies greatly. Whether they admit it, or not, all men are curious about cocks. It's why most boys have pissing contests and many jo with a friend. All men glance around in the showers and locker rooms. Any man who says he hasn't is a liar. All men (except the 3% that are 100% gay) are at least at least that level of bisexual. Most straight porn is primarily focused on the cock. This is the same porn that is mainly marketed towards men. Then there are those who fantasize about cock play, but would never act on it.
Then there are there are guys that just enjoy stroking and sucking each other. That's all they are interested in. Some that are more bisexual might add in some combination of kissing, nipple and\or anal play, Basically but they are still more strongly attracted to women and a hetero emotional relationship. It's only someone who is 100% bisexual that will have an emotional relationship with either sex. Just because a man is "all in", doesn't make him 100% bisexual. There is usually a stronger attraction to one sex.
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