The impact of finding out your spouse, boyfriend or girlfriend is cheating on you maybe the ultimate sucker punch. Everything you have invested in the relationship from emotional and physical commitment to trust and understanding seems to have been wiped out in less than an instant. Your mind is naturally racing and you are not quite sure what to do next. But for you that's not the worst part. The real shock is that it was with your best friend.

If familiarity breeds contempt it also has a tendency to give birth to temptation. Being in close proximity to someone (especially if there is some attraction) maybe too great a temptation for some people. That familiarity also extends to you since it's a given that both parties have a pretty good grasp of not only your innermost thoughts and feelings but also your movements and whereabouts.

This makes catching them cheating extremely difficult. It's almost like playing poker and everybody at the table knows what cards you have and how you are going to play them.

But it is not impossible. Many extramarital affairs that have taken every precaution to keep things hidden have been caught red handed by accident or a spouse who was a little too smart for both parties. What are some things to watch for?

1. Contact

You come home and they are there. Not that your best friend hasn't dropped in like this from time to time but now it seems more than usual. You also notice that it startles you a little bit. Don't necessarily dismiss that as jumping to conclusions.

Your instinct maybe trying to tell you that something is not quite right. Be doubly aware if you notice that phone contact increases or there seem to be more one on one conversations between your significant other and best friend. It's okay to wander into the conversation and ask what they are talking about. Take note of their reaction in body language as well as words.

2. Complimentary

Yes your best friend is attractive and they look even better when they are dressed to the nines. See what kind of feedback they get from your spouse. Are they paying more attention than usual or going overboard with the flattery?

Maybe it's reverse. They know your best friend is looking good but are trying way too hard not to notice. Again take note of their body language and watch for certain looks that pass between the two of them.

3. Examination or Bust

Undoubtedly, you have discussed many aspects of your relationship with your best friend. Where as before, your discussions may have involved some fair criticism, you now you get the sense that things are different. They seem to come to the defense of your significant other a little too quickly. Their questions may also get slightly more inquisitive. They want to know the specifics of where you are going to be and when.

Or it could be the opposite end of the scale. Suddenly the give and take conversations the two of you shared is replaced by unfamiliar and awkward silences. Are they hiding something? This might be a good time to do some cross examination of your own.

There is no way to ease the impact of finding out that your significant other is carrying on an affair with your best friend. It hurts to the core but sometimes living with the doubt and suspicion can be a lot worst. Therefore watch for the warning signs, trust your instinct and if what you suspect is true than be prepared to get on with the rest of your life.