Infidelity can happen to anyone. Here are a few tips for your readers to affair-proof their marriages. I call them 'the four P's? for prevention:

1. Be protective of your marriage. Avoid risky situations such as long lunches with a co-worker or drinks for two after work. Most people do not plan to be unfaithful.

2. Be positive. Look for what is right in your spouse and tell him or her daily. People who have love affairs are often looking for appreciation and affirmation.

3. Be polite. Always talk to your spouse with respect. Be careful what you say to each other and how you say it. Show courtesy and caring in the way you treat one another.

4. Be playful, and make fun, sex, and humor a mainstay in your marriage. Schedule time to play with one another, and have a 'date night? at least once a week.

Marriages can and do survive affairs, and many become stronger having weathered the crisis but not without pain and a genuine desire to recommit.

L.S., Ph.D., Seattle, Spokesman-Review, October 4, 1997