I'm going to try and keep this as brief as possible!
My friend was in a relationship with a man who is manipulative, belittling, emotionally abusive, and quite frankly, evil.
They were together for a year, she was at his beck-and-call, and in that time he cheated on her at least twice. Even after breaking up with her (20 months ago now) and having a new gf, she was still at his beck-and-call every time he was drunk or having a rough day and this was understandably getting my friends hopes up and devastating her every time it was nothing more than a bit of a booty call.
He'd say how much he missed my friend, yet refuse to leave his gf. If my friend tried to tell him how much he was hurting her and how she deserved better, he'd tell her to grow up and get over it.
One night early last December she went to see him, fully intending NOT to sleep with him, then sent me a text early that morning saying he'd been really drunk and had pressured her into having sex with him, and afterwards he shouted in her face that she was nothing but a slut and a whore. She was convinced she must be, just because he said so. After this I told her that he was being emotionally abusive, manipulative, and his behaviour was reminiscent of gaslighting, that she wasn't a slut or a whore, she didn't deserve this treatment and he didn't deserve her. She agreed with me, but still went back to him early January - the longest she's ever been able to say "no" to him.
On several occassions my friend has broken down to me because he's said or done something that has made her doubt herself and completely destroyed her self-confidence, convincing her she's useless. However, this has never stopped her from having sex with him, she always goes back.
He became extremely childish when she had an almost-one-night-stand with someone, again calling her a slut (despite the fact she didn't actually have sex with him) and wouldn't talk to her for a fortnight. My friend felt she had to justify herself to him and couldn't understand why he would completely ignore her if they bumped into each other.
I found out today that he's broken up with his gf and, according to my friend, "he's in a really bad way". I told her that he's a grown man who can take care of himself and if he feels like that he's brought it on himself and she should forget about it. Her reply was "But he's still a friend".
I've tried making her see that she doesn't need him (her reply is she needs sex and he's good at it), and pointed out that if she's hoping for a relationship with him that as he's been cheating on his gf with her, there's nothing to stop him cheating on her (especially as he's done it before) but she's said she'll keep it casual and not get emotionally involved again (even though she's never emotionally detached herself, despite her protests to the contrary!).
She's still totally wrapped up in him, putting his mental health before her own. I'm not even convinced he really is "in a bad way" and that he's just made it appear that way to her to make my friend feel sorry for him IYSWIM? Maybe I'm just being cynical, and maybe I should just leave her to her own devices, but it hurts me so much to see how he hurts her. Is there anything else I can do to help her, other than hold her hand when she needs it?