But after several mintues of interagtion, she finally admitted to being extremely sexual with the man, who turned out to be your nieces ex boyfriend.
I saw many men who reported that their wives were highly sexual beings, with a greater sexual capacity, and it simply turned the husbands on and pleased them to be able to see their wives sexually satisfied, to a degree that a single husband couldn't match.
In the last 5 years I may have mentioned it, in jest, maybe a half dozen times.
Be 100% open with her.