About 25 years ago a friend of ours (with two preteen girls) threw a nice big 40th birthday party for her husband and after everyone left he told her he was leaving her for another man he met on Prodigy. BTW, that man was also leaving his wife and kids. Creepy.
I know of two women who found out their husbands were cheating on them with men. Both women were shocked to find out because they never suspected. Both filed for divorce right away, of course.