Dear Mr. Dad: I’m an expectant father and something weird is happening. Ever since I found out that my wife is pregnant, my loyalty to her has started to waver and now all I can think about is going out and having affairs—especially with her best friend. I don’t know what’s happening, but I’m in desperate need of help—it’s driving me crazy.

A: Cheating in marriages is nothing new. And although there’s a stereotype that men are the primary cheaters, a number of studies have found that women are just as likely as men to stray. Cheating during pregnancy is actually pretty rare, but thinking about it isn’t. There are a number of interesting theories about why this happens.

  • You’re a grown-up now. I’m sure you’ve had more people than you can count tell you that, “your life will never be the same.” And they’re right, it won’t. There’s something about becoming a parent that makes you face that fact that you’re an adult, with responsibilities, expectations, and a lot less freedom that you had before. There’ll also be less hanging out with friends, less spontaneity, less money, less sex, and less sleep. That’s enough to make anyone panic and want to run away—even if it’s straight into the arms of another woman. Thinking about having sex with someone else can be a way of trying to regain some control over your life.
  • You’re not single anymore. For most people, getting married—or at least having a child with someone—means exclusivity, that you won’t be having sex with anyone but your spouse for the rest of your life. Fantasizing about having an affair may be your brain’s way of getting in a few more relationships before it’s too late—and of showing people that, yes, you’re still one sexy devil.
  • Feeling left out. Affairs during pregnancy (which some experts say are just as common among pregnant women as expectant fathers) are rarely about sex. They’re about feeling excluded. Men tend to rely on the women in their lives for emotional support. But when your wife is spending most of her time thinking about what kind of mom she’s going to be, how motherhood is going to turn her life upside down, and whether you’re still attracted to her and her changing body, you’re not getting the kind of support you were used to. Interestingly, when pregnancy affairs happen (and again, they’re quite rare), they’re often with a good friend of the expectant mother—someone who’s also feeling emotionally neglected by the mom-to-be.

I doubt that there’s an adult on the planet who hasn’t been tempted to cheat on their spouse or partner at one time or another. But, obviously, there’s a big, big difference between thinking about it and actually doing it.

Okay, so now that we know you’re completely normal, are you honestly worried that you’ll lose control and suddenly wind up in bed with someone else? If so, it’s important that you get some counseling. A lot of the issues that are triggering your fantasies now (like the increased responsibilities, the lack of freedom, the increased expectations, and the pressure to be the provider-protector) will still be there after the baby arrives and it’s best to start dealing with them now.

I strongly suggest that you go alone—and that you don’t even mention it to your wife. She’s got enough to worry about already and having you tell her you’re thinking about having an affair—at exactly the time when she’s counting on you most—will do nothing but harm.