9 Signs a Guy Is a Keeper

This seems like a no-brainer, but it's a good place to start. "It's very important that you two be able to have a lot of fun together, so a party boy or a screw-up will probably not work out for you," says Mira Kirshenbaum, a family and couples therapist and author of Is He Mr. Right? "No matter how charming he is, if he is still struggling to grow up, it will get very old, very fast."