My sisters bf left her. They had been together around 6 years and have two kids together. She had cheated early on in their relationship with her ex/other daughters father. He cheated with his ex/other daughters mother while she was pregnant with their 1st child but she is just finding out about it. She has previously been a cutter and has threatened suicide if he were to leave her (years ago). She isn't completely alone because our mom lives with her and she is still young (26). Any thoughts on what to say/do? I don't want her to go back to her other ex he was abusive.