Doug just couldn't understand it.

The 30-year-old bar manager had been on-and-off with his girlfriend, Kerry (both names have been changed), since they'd been students at Florida State University. And sure, she'd been jealous before—there was that time he was working as an assistant on an independent movie and returned home with a signed glossy of the lead actress, only to have Kerry hurl it out the window. But what the hell? Kerry was the most beautiful girl he'd ever seen, and three years ago they'd settled down in Asheville, North Carolina, to start building a life together. Then, last June, Kerry became convinced he'd cheated on her. One night, she forced him to delete every female Facebook friend she deemed good-looking—while she watched. "I had to choose between breaking ties with every attractive female friend of mine and giving her up," Doug says. "That's a really fucked-up thing to do. But I did it, because I'm committed to this girl."

But that didn't put an end to Kerry's trust issues. A month later, Doug let her use his cell phone to make a call, and she skimmed through his text messages, demanding to know the context of every one. Doug complied. But his explanations turned out to be moot—Kerry hurled his phone at a wall with enough force to shatter it completely.

At this point, it's fair to say, most of us would likely ask the same question of Doug: Are you fucking nuts, man? It's hard to imagine why any well-adjusted man with options would stick around for another fireworks display. But for Doug, the explanation is simple: He found Kerry's behavior erotic.

"I'm not a buff surfer from California," Doug says, looking back. (He finally broke free of Kerry this summer.) "So when you have the most beautiful girl on earth fighting for you? That's kind of—hot."

For most men, extreme jealousy is a deal-breaker—a sure sign that you're in for a lifetime of self-justification, surveillance, suspicion, and maybe even a torched Audi or two. Still, there's a certain Sid-and-Nancy appeal to knowing that your partner is crazy enough about you to check up on you. And lest you write off Doug's behavior as the isolated antics of a sucker, think back to the headlines last June, when Lindsay Lohan chased her ex-lover Samantha Ronson all the way to London—just two months after Ronson's family had reportedly inquired about a restraining order against LiLo. Ronson caved.