A mom who functions as a caretaker, financial adviser, champion, and friend all in one can be a huge bonus for a guy—especially one busy with work. Levey's mom carries—and freely distributes—all five of his business cards. "My mom pimps better than I do," he says. Maybe that explains why mama's boys can be such overachievers. Think Harry Truman, FDR, Bill Clinton, and Barack Obama. But couples therapist Rachel Sussman sees plenty of brainwashed men. "A lot of moms have their sons thinking, 'No one's going to love you the way I'm going to love you,'" she says. "I've been in sessions where guys defend their moms while throwing their wives or girlfriends under a bus. They have mothers who really guilt-trip them, and they don't always understand what it does to their relationships."

Ex-girlfriends of mama's boys often view their overbearing rivals as the worst kind of other woman. Claire, a 35-year-old woman who asked not to be identified by her real name, once dated a 38-year-old millionaire whose mom would come to his house every Thursday bearing groceries, then do his laundry and cook him dinner. She'd even nap in his bed. Claire accepted this for a year and a half—until the couple retreated to a luxury resort for a vacation. As Claire hauled the bags into the room, her beau walked out to the balcony to call his mom. "I heard him waxing poetic about the ocean view," she says, "and I realized it should have been me out there, the two of us taking it in together, instead of him on the phone with his mom."

When Levey meets a prospective girlfriend, he makes no effort to hide his cozy relationship with his mom. "It's a big part of me," he says. "I'm very close to my mom, and what she thinks about a person means a lot to me."

Women don't run away when they hear this sort of confession, Sussman says. Many think it's cute; it suggests that you'll treat them well, too. But, she adds, if you don't set boundaries, you're in for trouble.

"Whoever you're married to comes before your parents," Sussman says. "I'm talking for all couples counselors. We believe the predominant relationship is the marriage. If you have a parent who doesn't understand this, you need to reeducate the parent."

Mike Adamick, 33, a stay-at-home dad in San Francisco, agrees. He might go thrift-store shopping with his mom, maybe even try her Jazzercise routines, but he has his priorities clear. His mom will be joining him, his wife, and their 3-year-old daughter in a tiny apartment during a visit to Rome. But in four years of marriage, he has never once placed his mom's views above his wife's, not even when it comes to what movie to watch. "I don't want to make it a competition," he says. "To side with my mom over my wife isn't going to happen."