What could her/his SO's version of the story be? [Details inside].

I have asked a question on this before (Feel sorry for the third party?) but recently, after having read several questions on the subject on Fluther, I became interested in it again.
This is the (made up) story I used a man as the story teller, but it could have been a woman too, of course:
Hi, I am a guy, married with children for six years.
My wife, who used to be my manager in the supermarket that we both worked at, has been behaving strange lately.
For a few times already the last weeks she had, supposedly, meetings with potential business partners, but when she comes home she smells of aftershave and a couple of nights she didn’t feel like having sex.
Usually she has a big sex drive, by the way.
On top of the smells and the decreased sex drive, an old colleague of us texted me that she heard that my wife was seen by someone, having diner in a restaurant, supposedly with a man.
I should add that she has confessed to me, in the beginning of our marriage, that she cheated on her first husband once.
Do you think she is cheating?
What should I do?

Do we always believe the OP’s version of a story like the one above?

Instead of answering those two last questions in the fictional story I want to ask you what the version of this story from the fictional wife could be?