As for me I think one reason is that i've always had problems in bed when it came to fucking women. Yeh, i did get pretty good with my tongue and was able to pleasure women that way. As i've gotten older my penis problems have just gotten worse. What choices do you have when you can no longer get hard enough to fuck. Its clear to me, and I have accepted, that my days of being the "pitcher" are over. And I admit, in part due to a porn habit, i now do get turned on by seeing a nice big hard cock. So, not only do I have fantasies about licking a woman's pussy, but also fantasies of licking her pussy after she's fucked another man, and also fantasies about sucking cock ( and .... ok yeh, fantasies about being fucked either by a woman with a strapon or by a man).