My new boyfriend travels a lot for work. Before he left on this trip, he gave me his weird onesie lounging garment. It's this disturbing "As Seen On TV" thing called a Forever Lazy. It's like a fleece blanket, but with legs, a hood and a...umm....back flap for easy bathroom access. I was hesitant about taking it, but he said, "Take it! It's so comfy! It's the bomb!" Of course, I don't wear this weird thing, but it smells just like him. I've found myself cuddling up with it and sniffing it. Like, a lot. And it's not just about missing him; it's about the smell. I feel like a serial killer! What is wrong with me?!

--I'm Weird

Welcome to the decline of civilization playing out in a single garment. If a grown man who wears one of these things says something like "Let me slip into something more comfortable," you've got to think, "What, the womb?"

What seems weird to me is that you're able to have sex with a man who wears a giant romper. What doesn't seem weird is your sniffing Mr. Baby's onesie. This suggests that you two might be a pretty good match, at least genetically -- which isn't to say your genes and his have lots in common. Studies by Swiss biologist Claus Wedekind and others have found that women seem to prefer the body odor of men whose genes are dissimilar to theirs. Which sounds so hot: "Hey, baby, I love how genetically dissimilar you smell in the morning."

It's a set of immune system genes that matter. They're called the major histocompatibility complex, or MHC. "Histocompatibility" is a mouthful, yes, but it's really just the Greek word for tissue -- "histo" -- bumming a ride on "compatibility." MHC molecules are basically immune system security guards that sound the alarm on incompatible stuff in our bodies -- icky infectious microorganisms that don't belong in our "tissue" (really, our cells). If you and a genetically similar man have kids, your combined MHC genes will only be able to recognize a very similar, limited set of trespassers. But with a genetically dissimilar man, the immune systems of any kids you have will have a much larger force of security guards, able to recognize a much broader group of icky invaders.

Regarding your onesie sniffing, the most interesting, relevant finding on MHC is by experimental psychologist Christine Garver-Apgar and evolutionary psychologist Steven Gangestad. Instead of just testing individuals as previous studies did, they tested couples. They found that as the proportion of MHC genes that couples shared increased, women were less turned on by their partner, cheated with more men, and were more attracted to men other than their partner, especially during their most fertile time of the month.

In other words, it's a very good thing that you're into how this guy smells -- so much so that you can overlook the fact that he's a grown man who wears a onesie made from some fabric cousin of the airline blanket. Here's to your living fleecily ever after with your new man. But should this not work out, remember that smell is important, and look for a man who also smells good to you -- maybe even one who isn't afraid of hard work, like the agonizing chore of pulling on both sweatpants and a sweatshirt.