It happens so quickly: You’re walking down the street, you see a familiar face, you go in for a friendly handshake…and you’re greeted with a sloppy two-cheek kiss and an embrace befitting long-lost lovers.

Granted, if you grew up in an affectionate family, this may feel normal. But for those used to less demonstrative environments, a situation like this may feel slightly uncomfortable (if not a bit Soccer Moms Gone Wild!). It’s even more odd when it takes place with a comparative stranger. So how do you avoid a personal-space invasion without coming across as a wet blanket?

First, find another way to greet the other person. “Most people establish their personal boundaries with body language, so extend your right arm for a handshake as soon as possible and, if necessary, take a subtle step back,” says Peggy Post, etiquette expert and author of Emily Post’s Etiquette, 17th Edition (HarperCollins, $28, www.amazon.com). You’ll be doing the person a favor, because she won’t have to worry about how to approach you.

Additionally, make solid eye contact, and offer a big smile. “That can be just as friendly a greeting as a hug and a kiss,” says Post. If the person still comes in for a smooch, offer your right cheek to avoid potential lip contact. Finally, if a repeat offender really makes you feel uncomfortable, address the situation with a little humor. Laugh and say, “Whoa, there! That’s more action than I’ve had in months.” She should get the hint.