Trust is essential. If you don't have trust in your relationship you're headed for a world full of hurt that no amount of cookie-dough ice cream is ever gonna fix. You don't want to go around snooping through your honey's things looking for evidence anymore than you want him going through yours. But what happens when you find out for sure that your beau's been smoochin' another? Here are five tips for dealing with a cheating heart.

Other than mouth-to-mouth resuscitation, or the "we're practicing for the school play where our characters kiss" excuse, there aren't many believable alleys he can travel down to get out of this one. But you need to at least say you saw what happened and that you deserve to know why.

2. Decide if you want to believe him.
Did he say it only happened that one time? Has he promised not to let it happen again? Has this sort of thing happened before? You need to weigh all the evidence and choose for yourself if you can truly trust him again. There's no hard rule for cheaters. Some girls always give a guy a second chance; others kick him to the curb as soon as he strays from the relationship. But you must make your own boundaries and let him know exactly what you will and will not tolerate.

There's an expression that might help: "Once, shame on him. Twice, shame on me."

3. Don't fight fire with fire.
Making out with someone else to get back at him isn't going to do you any good. Just because we've seen it work on TV and in most movies, doesn't mean in reality it's a sure-fire way to get back at your beloved. You don't want to live the life of a "Jerry Springer Show" guest, do you?

Plus, you might end up hurting some innocent guy who doesn't realize he's just being used in your revenge schemes.

4. Talk with your gal pals.
You're not alone. Having a boyfriend who likes to smooch other ladies happens to a lot of girls. Chances are that one of your friends has gone through the exact same thing. Having a heart-to-heart with a pal who's been there can be really good for the psyche. And who knows? Maybe she can give you some useful insight.

5. Believe in yourself.
Even though it truly sucks to be cheated on, don't immediately blame yourself. Some people can't commit to one person, or are simply afraid of being in a serious relationship, so they cheat. It's just a fact of life. The more time you spend trying to figure out what went wrong, the crazier you're going to feel. Know that you're an amazing person, and that sooner or later you'll be dating someone who can appreciate you.