This exact thing happened to me but my wife accused me of cheating. I live in a culdesac with 5 other neighbors, one neighbor has a child the same age as my oldest. We used to text each other about play dates for our children, that’s all we ever discussed through text and our relationship was only because we had the same aged children. Other people in our culdesac texted me as well, even my wife’s friend who lives directly across the street and is another lady. I asked my wife why didn’t she have a problem that her friend was texting me and her reply was “oh, she’s happily married”. That shit was crazy!! We ended up going to marriage counseling because I told her I did nothing wrong and whatever she was feeling was all in her head. I don’t text anyone in my culdesac anymore it’s just not worth the drama. She occasionally brings this make believe affair up periodically.