It probably starts in the high school locker rooms, or even earlier in some cases. It surely starts from the overarching tendency toward homophobia that is handed down to youth from those who learned this system in turn. The message is that there are some things it’s ok to do during sex and some things are definitely not kosher. For a guy, putting anything up his butt is one of the no-nos.
Lucky for the enhanced pleasure of many men, some do outgrow this belief or simply realize that it is not a useful prohibition. It can be something they discover on their own in a private finger-fucking session. Sometimes a porn magazine ad for a butt plug might finally pique the curiosity. Others just don’t even think about going for it, so running into a woman who likes to penetrate her man can become a challenging situation for both of them.
One of the early roadblocks that a woman can help dispel for her partner is that a guy who likes being penetrated is not necessarily gay. As a matter of fact, the act of anal penetration has nothing whatsoever to do with being gay. If the woman is really into the idea, she can let the man know that it would really turn her on. Dispelling the gay myth will probably naturally follow as a close second. In order to help him feel secure, she can promise to let him feel her womanhood while she plays with his ass. With a woman whose voluptuous breasts are spilling out all over him lying on top of him, it will be hard for him to imagine that he is gay as she gives him an ass probing.
For some men who have had a long-held fear of ass play, it may not be best for them to start out with another person. Once his wife or girlfriend has expressed interest, he may want time to get used to the feeling and response and potential of that orifice at first by himself. He may try using an enema if he is worried about soiling, then trying out a small butt toy. If he finds that he enjoys it, he may decide that this sexual expression might be something he feels ok about sharing.