A woman asked this question on an online social networking site:
“What constitutes unfaithfulness in a marriage? My husband works with a female who I do not trust (with good reason). When I ask him about her he tells me he has not seen her or runs into her “once in a while.” I found out that they have had lunch recently (at work) and that he lied and said they hadn't. He tells me nothing is going on. Do I believe him??”
And I replied:
No you can’t believe him. Whether or not sex is involved isn't the issue yet. People who have nothing to hide, don't hide. He has chosen an allegiance to her. So she is privy to information that he has decided you can't have access to. Cheating - if nothing more he is cheating you out of trust and cheating you out of certainty - is when you deny someone something they have earned through merit, deed, ownership, or justice. As a spouse, you've earned the right to be the first ear he whispers in. He is cheating you out of your place at his side. If it's nothing - why does he feel the need to hide something? It's not as if he is a priest and vowed a confidence.