Kate found out her husband was having an affair the same week he asked her for a divorceshe didnt see it coming. She told me, My gut was telling me that things werent quite right, but Bob had convinced me I that was just paranoid and insecure. I had no idea he was such a good liar. He talked me out of my suspicions.

I asked her, Could you make a list of his unusual behaviors? New actions that werent necessarily badjust odd. But now, looking back, you see them as signs that he was having an affair.

Here is Kates top-ten list:

1. About six months ago, he started working longer hours and having more client dinners.

2. When he was home, he would seem restless and often claim he had work to do, so he spent a lot of time in the denwith the door closed.

3. He started some new patterns that I thought were wonderful. He took the dog for long walks, and offered to run errands for me in the evenings. If I commented that I wished I had some cookies for the kids lunches, hed say, Ill be happy to go to the store for you. I found out later that hed call his mistress on his cell phone while he was walking or running errands.

4. He gave me a goofy, silly card for my birthday instead of his usual romantic, sentimental one, and he only signed his namenot Love, Bob.

5. Our sex life lost its sizzle. On the rare occasions when we did make-love, it felt awkwardly coldjust a physical act, not an emotional connection. I think he may have felt as if he was being unfaithful to his girlfriend by sleeping with me.

6. He started referring to a person at work named Pierce. He would tell me how funny and talented Pierce was. That was his mistresss last name!

7. He started to skip desserts and be very careful about what he atehe lost weight and started exercising.

8. He dyed his hairto cover the gray. She is twelve years younger than he is.

9. He seemed more short-tempered. Things that didnt usually bother him suddenly did. He was especially impatient with the children.

10. After I saw the way he reacted to her at a company party, I asked him if there was something between them, and he lied to my face. Looking back, I know he lied to me about credit card and cell phone bills, and that most of the new clients hed been taking to dinner were not clients at all.

Kate summed it all up: I wish Id been more alert. I just didnt put all the pieces together until it was too late.

When Secret Service agents guard the President, they continually scan the crowd. Theyre looking for unusual movements or odd behaviors that may be an indication of danger. The agents have studied how innocent people usually behave, so they can spot a person whos acting guilty. We can apply some of these lessons to guarding our marriages.

These warning signs may indicate an affair:

1. Changing eating and sleeping patterns;

2. Wearing a different style of clothes;

3. Starting arguments or becoming very passive;

4. Working longer or different hours;

5. Pulling away from normal activities and extended family;

6. Taking more showers than usual;

7. Comparing his or her spouse to other people;

8. Hiding credit card charges and cash withdrawals

9. Taking off his or her wedding ring.

10.Becoming secretive or defensive about phone calls and emails

You dont need to be paranoid or to see things that arent there. I dont recommend that you spy on your spouse . . . but if you need to, feel free. It would be wise, however, to be on guard.

Guard Yourself

Affairs begin in many ways and for many reasons, so we must be always on guard for the slightest hint of temptation. Because hints turn into flirtations, flirtations turn into attractions, attractions turn into affairs, and affairs turn into disasters

When youre guarding your marriage, youre not guarding just your spouse, but guarding yourself too. I rationalized my way into a boatload of trouble because I thought; The rules dont apply to me. Im smart, I have self-control, and I can stop before it gets too far. All lies!

My affair began at work, so Im an expert on workplace temptation. Once, the most common type of office infidelity was between male bosses and females who were lower-ranking employees, but thats changed in the last ten years. With more and more women working, the most common office affair is between coworkers. The man I had my affair with (Jake) was not my boss; we were both sales repsequals.

My relationship with Jake started innocently. I noticed that we laughed at the same things, and he noticed that we liked similar music, so we started to sit together at lunch. We were just friends . . . until we werent.

I remember the first time we went out of the friendship zone and into the danger zone. We were sitting next to each other at a sales meeting when his leg brushed up against mine. I felt a spark at the contact point and was a bit disappointed when he pulled away. A few minutes later, he shifted slightly in his chair and his leg, from knee to thigh, pressed gently against mine. I liked it, and I didnt pull away.

I should have. But because I didnt, I sent him a signal that I was unguarded. We both began to look for excuses to be together. If Id not responded to his flirtations, I would have avoided the biggest regret of my life.

Coworkers sometimes work on projects or solve problems together, and the resulting closeness can build teamworkbut it can also build a feeling of intimacy. If you feel an attraction to someone in your office, consider a transfer to a different department, a different position, or maybe you should quit. No job is more valuable than your marriage. I knew that I could not continue to work with Jake without being tempted, so I quit my job the same day I confessed my affair to my husband.

Be honest with yourself. If youre dressing to please someone at else or lingering in the parking lot hoping that person will ask you to lunch, stop now, before youve gone too far. If youre in doubt as to what conduct is inappropriate, ask yourself, Would I do this in front of my spouse? And if youre still not sure, ask yourself, Would I do it in front of GOD? (You are, you know.) Here is a simple rule to keep you on the straight and narrow: If youd have to hide it or lie about itdont do it!

The key to growing effective guarding hedges is to be honest about your weaknesses, both as individuals and as a couple. Set up distinct boundaries and enforce them. If your spouse reminds you of the rules, dont be defensive or point out your mates faults; accept his or her correction because its for the greater good of the marriage. Some of the most difficult phrases to sayyoure right and Im sorrycan save your marriageand your love.

When Secret Service agents guard the President, they regard the Presidents life as more important than their own individual lives. Guard your marriages in the same way. You may be required to sacrifice part of your individual lifehobbies, profession, TV time, computer time, sports activitiesto strengthen your marriage. If youre both willing to make your marriage a priority, however, and guard it from internal and external dangers, your home will be a safe haven.

Adapted from Avoiding the Greener Grass Syndrome: How to Grow Affair Proof Hedges Around Your Marriage (Kregel Publications 2004)