Frustrated by his relationships with women, convinced that romantic relationships with men would be easier, and figuring that if he never tried it he'd never know whether it was for him, Robinson got into a casual relationship with a "really attractive, interesting" guy for about two months. After the first time they had sex, "I thought, 'Well, that wasn't as weird as I thought it would be,'" he says. "I didn't recoil from the experience."

After that relationship fizzled, Robinson dated another guy but eventually realized that he wasn't gay. "It just didn't fit," he says. "It wasn't what I ultimately wanted." The switch back to women wasn't complicated, in part because he was never officially out.

But for some men the sexual confusion is a little longer-term. Bob (not his real name), a 33-year-old artist from Los Angeles, decided he was gay when he was about 10. Although he had sex with girls in high school, an extremely close friendship with a neighborhood boy, combined with homophobic taunts from his sports coaches, only strengthened his belief that he was gay. He wasn't wholly convinced he'd been right until he was 25 and went on a date with a girl but ended the night by going home with a male architect the two of them had met at a bar.

Then, while he was in his second relationship with a guy—during which he would have to fantasize about women in order to have an orgasm—Bob realized his decision had been premature. "And finally it hit me when I was in bed with the guy I was [dating] and he said, 'You're not into this.' My dick wasn't hard. I was like, 'I'm not gay, I'm not gay, I'm not gay.' It was like the flip scenario of when I thought I was gay."

While these men all think the switch from gay to straight was a definitive experience, some experts are skeptical that such a turnaround happens in any but the rarest cases. "I've only run across men who came out of the closet and pursued their gay identity but couldn't withstand the pressures of family and society so returned to being closeted and heterosexual relationships," says Ian Kerner, Ph.D., a sex therapist and the author of Sex Detox.

Nevertheless, instead of trying to run from their pasts, these men feel extremely grateful for having gone through what they did—and some even believe it makes them all the straighter. "Experimentation adds to your perspective—it doesn't limit you," says Rothenberg, who, along with Crabtree, transformed his experience into Regretrosexual: The Love Story, a two-person play that they perform to sold-out crowds in Los Angeles. And while she may be married to him, Crabtree isn't necessarily doing much to perpetuate Rothenberg's heterosexual image. When Rothenberg is informed that the blue patterned shirt he's wearing looks a little flamboyant, he sighs. "My wife picked it out," he says with a smile.