Yes, I have heard of this often....sometimes it began with elders giving 'spiritual support' to sisters, and then it turns into something sexual. In my case, my first husband & I were good little virgin JWs...we moved to a bigger congregation where his brother went. His brother was known to hit on any gals, especially non-JW. He was married. Well, he was also in a 'relationship' with an widow who was about 10 years older than us....who had also tried to break apart of couple of elders' marriages. She almost succeeded with his marriage. Instead, they were told to stay away from each other, and we were new in the congregation and didn't know all that had gone on....and he asked us to befriend this sister, as she needed friendship. He took all the blame for their relationship and said she needed us. She became my instant friend and eventually my husband's best friend....too much of a friend. We divorced and they moved in together...until her drinking and blackouts and throwing things at him became too much for him.
I have the firm belief that many times things like this happen because of the sheltering and being naive about relationships with members of the opposite sex in general. When you are raised as JWs, you truly don't get to experience normal relationships and get all mixed up...sometimes marrying for the wrong reasons to people that you don't really know.....then others come along and you either find them more compatible or they can be like predators and you don't know how to identify them and you can get caught up with them and their schemes.
One of my best JW friends (who is now DA'd for many years) was not raised as a child as a JW and she was much more keen on seeing people for who they really are and was more balanced in her relationships because she had experienced real life and real people.
Just my thoughts.....
'Alana'