Ussually I do not post in this forum but I like to read here.
This situation made me think.
I would like to share a experience I had.
Several year ago I had a very good relatiohsip with my boyfriend, until his mother found a boyfriend also. ( She was divorced). We used to hang out together ( 4 of us).
Once this guy, my boyfriend’s mother’s boyfriend told me that he liked me so much.
I did the same than you: told him that I loved and respected my boyfriend and respected also his mother, and I did not want to have anything with him. Anyway he agreed but not too enthusiastically.
This situation turned out to be a very bad traumatic situation. This man was very selfish, very bad person. He began to tell everybody bad things about me. He told my to boyfriend he had seen me with another man in a hotel!!! ( A complete lie) Also he told to me boyfriend he should not be so loyal to me and he introduced another girl to him. Eventually we broke up after very ugly situations happened.
I learned to observe people and be very careful.
My recommendations to you: do not say anything, but pay attention to this woman behavior . It is clear that she 1) or is very selfish and just want to satisfy her desires, 2) she is very confused, 3) she does not love her husband and 3) she does not care about the friendship with your wife and you, 4) all of the above.
I really recommend to observe her behavior, to try to learn what does she talk with your wife, how does she behave with her husband etc.
You need to learn if she is going to forget about this situation and everything is going to be fine or she can be a trouble maker.
Be prepare to observe her behavior. Avoid to be alone with her, and improve the communication with your wife. Ask your wife what is the general impression she has form this woman.
I wish everything is fine for you..