Friend has been messed about by this cheat for more than a decade
They were "together" for three years until she discovered he was married, the day he was supposed to move in with her. I genuinely believe she knew nothing about that, she was completely floored by it.
Went back to his wife and they didn't see each other for a while. In the meantime he has a child with wife.
They get back together, wife knows all about and he's going to leave, but wife is ill, child is ill, complications at work mean he's not financially able to leave, it's not quite the right time etc etc
Several years later he has officially "moved in". Except he never has the child to stay and he's now spending several nights a week at a sick elderly aunt's house to provide care.
This apparently demonstrates that he has a good caring heart, despite everything...