Re: husband interested in wife’s sister
If he’s just giving the evil flirty smile I think (and this depends on now much sharam the man has!) if he becomes aware of the fact his wife has noticed he may simply switch off the unacceptable flirty smile.
Is this going to create a problem between the girls family and the son-in-law? If you think this will be the case I seriously think the bahaviour needs to be addressed. She (the wifey) needs to speak up.
Is the wife isn’t satisfied with her husband let’s hope this isn’t causing his wondering flirty eye as a way of bigging himself up. Just a thought.