Updated

Whether you are playing cards or asking the pool boy to come in for a cool drink (wink, wink) the word “cheating” means the same: not abiding by the rules you agreed to when you got into the game.

So cheating in a relationship is when you have promised your partner something, and you break that promise. (Note: the “something” is between the two of you, we aren’t here to judge.)

As with most things, figuring out the rules beforehand is in your best interest. Not sure you cheated? Notice your significant other’s reaction: When you come home from the strip club, if you find Linda Blair, head spinning, smoke and fire coming out of her ears (think The Exorcist) — you can bet she thinks it was cheating. If she shrugs because “that is what guys do at bachelor parties,” she just doesn’t want to hear the details, then nope, it wasn't. (I’d still strongly recommend you figure this out before the party).

Here are some other cheating questions I often receive:

1. Is watching porn or having a “Second Life avatar” cheating?

Again, if you are a woman having an “affair” with another avatar on your computer and your husband doesn’t mind because it’s not in the flesh, then you two have decided that is not cheating. In other words, different strokes for different folks. Some couples may consider a spouse entering a chat room or having a lap dance cheating; others may not. My advice? Sit down, face-to-face, with the seriousness of a corporate board meeting, set the rules for your relationship, and follow them to a T. Need to renegotiate? Reconvene before you make any bad decisions. Being honest about what you expect and what you will tolerate is a conversation every couple should have, 100 percent truthfully.

2. Can you get over cheating?

Is it your goal to stay together or to co-parent? Is it your goal to win back the person’s trust? These are two different things. Couples may realize that their marriage is not working out, but they still love their families and want to co-parent well. Putting “the incident” in perspective is very important. The big factor that differentiates cheating that is a bump in the road and cheating that is a mountain, is if it was a one-time thing (and yes, one-time things do happen), or if it was a long-term relationship/multiple affairs. Either way, spouses must decide what is and isn’t acceptable for themselves. And a long-term affair or multiple affairs by one spouse could signal a problem that cannot be fixed and must either be tolerated or not.

3. My spouse’s suddenly lower libido has got me thinking about cheating. Is this normal?

Rather than cheating, try identifying the problem. There are dozens of reasons one’s libido can flounder; in a national survey I did a few years ago, the top reasons included sleep deprivation and weight gain. It’s hard to feel sexual if you are tired and/or overweight. There are hundreds of medications that have lowered libido as a side effect. Perimenopause, menopause, and in men, andropause (sometimes referred to as a male menopaouse) can also lower libido. Financial difficulties, anger and resentment, stress and depression also are prime libido killers. The main question is, is your spouse willing to parse the medical and psychological and look at this as a couple’s problem that needs attention? If he/she is, use CSI stealth to go through each of the above to find the culprit. The good news is that remedies like testosterone patches, and small doses of antidepressants that also act as libido enhancers, are readily available. If you don’t elicit much enthusiasm for your significant other in figuring it out, get to couple’s therapy fast – often having a sexual referee help negotiate this hot topic is the best solution.

Dear Doc,

I’m a single dad and want to give my teen daughter a book about sexual health. I mean, I will still be around to talk to her but want something with a lot of facts and experts that she can use as a resource. I’m scared about her getting misinformation on the Web or through her friends.

— Desperate Dad

Dear DD,

You are right to be worried; both the Internet and friends have some really bad information. Plus teen years are notoriously impulsive, short-sighted and just gosh darn illogical. Get her the fantastic classic, “Our Bodies Ourselves: A New Edition for a New Era” by the super-reputable team at Boston Women’s Collective (at pretty much any bookstore!). And let her know you’re also there for her – no matter what the question is.

— Dr. B

Dr. Belisa Vranich is a psychologist and sex expert. She is the author of three books, including her latest "Get a Grip: Your Two-Week Mental Makeover," which is in stores now. Do you have a "Dear Doc" question? E-mail Dr. Vranich at DrBelisa@gmail.com and check out her Web site at www.drbelisa.com.