Around 22% of married men & about 13% of married women cheat, according to a Universityof Chicago study. (Opinion Research Center).

Here are some of the common signs that your partner is cheating: 

• he/she's working late a lot
• he/she's's suddenly taking trips you can't go on
• he/she's got new hobbies that don't include you
• mysterious phone calls with hang-ups
• credit card bills for unexplained hotel stays or gift-type items
• less sex
• he/she's's more distant, angry or picky 

     But the good news is that there are plenty of couples who weather an affair & actually improve their relationship.  Why?  When you face loss, love can grow.

 Here are four steps you can take when you think your partner is cheating:

1.  You need to empower yourself and knowledge gives you power.  Ask your partner.  Be cool and watch the way he/she acts.  Your partner may look away, change the topic, bite his/her nails, or give you one of two strong defensive reactions: acting like a victim, saying something like, "How could you say that after I’ve been so good to you?"  or, getting angry & even accusing you of cheating.    These may all be signs of an affair. 

Of course, if you're the jealous type or you've been cheated on in the past, your jealousy may not be based on what is really happening in your current relationship.  In that case you need to work on your own issues. 

2.  If things don’t feel right, trust your gut instinct and find out the truth.  If you're married or living together, make sure you know where all the money is--check the various bank accounts and other assets to protect yourself and see if there've been any unusual withdrawals.  Go through the joint credit cards looking for hotel or other mysterious charges; look at the phone bills; go to where your partner is supposed to be--show up when he/she’s 'working late' or 'playing poker.'  If you suspect a certain person, go to her/his house and look for your partner's car.

3.  Assuming it is safe, get your courage up and  present the evidence to your partner.  Get him/her to tell you as much of the details about the affair as possible.  Research has shown that cheaters who tell their partners the full details are more likely to save their relationships.

 4. After it’s all out in the open and the relationship hangs in the balance, you need to make the hard decision.  Do you want to be revengeful and end it all or do you want to make it work?   Coming face to face with the loss of a relationship can help people mature fast--many times the cheater can become a new person who is truly remorseful and wants to make it up to you.  This is a good time for both of you to start therapy. 

      In some cases your partner may want out or he/she may not be willing to change.  If so, you may have to leave.  You can use the pain and anger as fuel to create a new life for yourself.  Many have.  The best revenge is a having a great life!

      Take a real  look at what’s going to make you happy.  Do you want to create a loving monogamous relationship for yourself?  If you commit to this for your own sake and your partner is remorseful and wants to make it up to you, the crisis can slowly become an opportuniy.  After he/she stops the affair, both of you need to continue working together on your issues.  If you do, odds are the relationship will not only survive, it will get better. 

     Diana Kirschner, Ph.D. is a top psychologist who is recognized as a national expert on love and relationships. Dr. Diana spoke with Diane Sawyer on Good Morning America on 'Cheating'. Click here for a clip! 

  News Flash: Dr. Diana has developed a new Sex & the City Dating Type Quiz.  Are you more like Carrie, Samantha , Miranda or Charlotte? To find out, just Click Here!