Is it Lust or Love?

The guy in your life makes you happy. But is he really the man you were meant to be with? Here, how to tell.

You know it's lust if:

You don't mind when he's mysterious. Maybe he replies to only one out of every three text messages you send him. Or maybe he won't give detailed answers about where he went last night. But instead of being annoyed, you love the challenge.

You spend all day daydreaming about your lover. You might even lose your appetite and need less sleep thanks to the surge in feel-good brain chemicals. Yes, all relationships should make you feel good. But if you can't focus on work and other real-life obligations, the relationship won't last.

You'd hook up with the new guy at work. He's young and hot, you're young and hot—it's a no-brainer!

Before a date, you change into sexy panties.

One day, you notice the stray hairs on your lover's neck, his weird-shaped toes or the way he breathes before you kiss. And you get grossed out.

You know it's love if:

You can read him like a book, but it's like flipping through a best-seller. You don't need to know all of his secrets (after all, do you really want to hear about how he fantasizes about Salma Hayek?), but you have the 411 on your man—and you love all the info.

This starstruck phase soon gives way to a stronger, less "I need to be with you siempre" bond. Your nervous system produces different hormones that help your brain understand, "Hey, this guy and I are going to be together for a while, so it's okay if I concentrate on work, too."

You realize that fantasies are just fine, but real-life affairs aren't. You'd never want to hurt your amor like that.

First off, isn't every night with your man kind of a date? Secondly, what's wrong with cotton undies?

You don't particularly love his feet, but you've massaged them. After having a margarita first, por supuesto.