Dear Amy: I married a lovely man two years ago. We lived together for three years before marrying.

We met as his first, long-term marriage was falling apart. We are both 70 years old. We spend most of our time together, but my husband has always kept most of the other parts of his life a bit removed from our marriage. He insists that he is faithful.

In doing our tax prep, I found that four “visits to his dentist” are nonexistent, according to the insurance company.

I believe he has lied about where he has been on those days when he claimed to have been at the dentist.

We have, ad nauseam, discussed being faithful.

I have tried to trust him, despite knowing that he cheated on his wife.

How do I deal with this situation?

Do I let this go, do I hire a private investigator, or should I just leave him knowing that secretive behavior is going to ruin my emotional well-being?

– Sad Wife

Dear Sad Wife: You don’t mention other examples of behavior you believe is “removed from your marriage,” and so I wonder why you leap so readily to unfaithfulness as the root cause – unless, of course, you were your husband’s affair partner when he was unfaithful to his first wife.

Perhaps you were his phantom dentist during his first marriage?

If so, you detect a pattern of deceit because in the past you were a part of it.

I can think of many activities your husband might be doing during his non-existent dentist appointments which he might want to keep private, including pursuing sex with another woman – or man.

I do know this: Most couples married for two years do not have “ad nauseum” discussions about unfaithfulness.

Furthermore, I don’t think most couples double check on their spouse’s various appointments to the extent that you have – unless your husband was claiming dental expenses that don’t exist for tax deductions. If that is the case, then you could add fraud to the possibility that he is a philanderer.

Yes, there is an extreme lack of trust in your relationship, and before hiring a private investigator – or leaving altogether – you two should sit down with a counselor.

If your husband won’t go, you should seek therapy on your own. If your gut is telling you that your husband is unfaithful, therapy will help you to decide what to do next, because you’re right – staying in this marriage without change is not at all good for your emotional well-being.

You can email Amy Dickinson at [email protected] or send a letter to Ask Amy, P.O. Box 194, Freeville, NY 13068.