In the early nineties, Dan Rothenberg was having a gay old time—literally. A rising comedian in San Francisco, he spent his nights at clubs in the Castro, where he discovered, to his surprise, that he was "a bit of a boy magnet." Rothenberg, then in his early twenties, was for pretty much the first time in his life finding hooking up with people easy. A regular at the Stud's disco night, he was known for starting off his routine at local comedy clubs by saying "I like my women like I like my coffee . . . I don't like coffee." Fifteen years later, he sits outside a West Hollywood Coffee Bean and Tea Leaf reminiscing with a woman about his days as an out-and-proud gay man. The woman happens to be his wife.

Rothenberg and Colleen Crabtree, both 35, met seven years ago. Five or so years before that, Rothenberg was paralyzed by fear over the realization that he wasn't actually gay. Although it took about a year to admit to himself that his Castro days were over, one incident stands out. "I happened to see a female friend getting dressed," he says. "I remember watching her and thinking 'There's no way words can describe how much I want that.'"

Despite the insistence of many—straight and gay—that switching between sexual preferences can't technically happen, Rothenberg isn't the only man to have believed he was homosexual before deciding that he was wrong. These aren't gays who attend faith-based programs to be "cured," or bisexuals who rotate between male and female sex partners the way the rest of us alternate pairs of shoes. And they're not the type who hide gay urges in public while privately trotting off to the local bathhouse.

For Andrew Brin, who grew up in Milwaukee, it was all about girls—until he had sex with a guy at the end of his senior year of high school. "It was fun and I had a great time, but I remember having the feeling that I was doing something that wasn't right," he says. In his early thirties, Brin started dating a man and came out to his brother. When he later fell in love with a woman (who was at the time a lesbian) and realized he was straight, he didn't inform anyone that he'd been waving that rainbow flag mistakenly.

And although there aren't statistics to show how many men go through a similar sexual shift, anecdotal evidence suggests that some men who consider themselves to be gay experience this kind of change not because of sexual experimentation or peer pressure but because they decide that they want to sleep with women instead of men.

For Ethan Robinson (not his real name), a 37-year-old film editor from Los Angeles, chasing women during his post-college years became a chore. "If I went to a gay bar I got hit on like crazy, whereas at a straight bar the women all but turned their backs," Robinson says. "At gay clubs you danced, you had fun. At straight clubs, you sat around, posed, and tried to affect a degree of indifference."