Bear with me, this is long.
My life-long best mate's husband clearly has some sort of NPD (sometimes charming, selfish, controlling, quite capable of lying black is white to suit his own ends) and has been emotionally and psychologically abusive for quite a while. My friend has made herself smaller and smaller over the last few years. She's also been assaulted a couple of times in the past (I found this out long after it happened).
I had a feeling something was really off almost since the beginning but she had 'laugh it off' excuses for all of it. Until this last few months she's never really said anything openly negative about him. She's quite isolated already, she's a professional artist who spends 99% of her time alone and they live on the other side of the world (he's from there). I worried if we fell out she'd really be alone with this, so I didn't push with asking anything. She's a strong person who's been through a lot so I believed she could handle him. They also seemed sort of happy, or at least, resigned and stable.
Recently the husband's behaviour has got very scary. Aggression, ice-cold, openly mocking and deriding her, jealous of her successes and seeming to want nothing to do with her. Then she found out he was having an affair. He's okay with the kids, obviously the behaviour towards my friend makes the house an uncomfortable place to live but he mainly restricts his behaviour to unpleasant comments and ignoring her, the worst anger and abuse are targeted at her when the kids aren't there.
He was initially remorseful although he said he loved the affair partner and wanted her instead. Then he hit her with the full script; he was driven by the problems within their relationship to have an affair. That they should never have been together. That he loved her but wasn't in love with her. Almost immediately though, when she said anything he didn't like he came back with appalling verbal abuse, tore her personality apart, called her a cunt repeatedly. When she tried to discuss separating civilly it didn't happen. If she pushed it, it just got out of hand. He doesn't hit her but she's clearly frightened of him. His position seemed to be that he was the victim and if she wanted to go, no-one was stopping her. No genuine apologies, only deflection and justification. Somehow everything always seems to be her fault.
She stuck to her guns and said she wanted out but he's suddenly done a 180. He has persuaded her to keep the affair (which he says is over) secret from his extended family (for the sake of their kids, apparently, so she hasn't confided in anyone apart from me) and now he's sort of pretending it didn't really happen and it's all fixable and she's over-reacted. Promising the earth, full emotional blackmail about the kids etc.
I'm very worried about her safety if she stays, and I'm also worried about her kids. She's clearly terrified of what divorce will mean for her and do to them. To complicate matters she has nowhere to go and can't leave the house, she's under constant pressure. She also had a violent childhood and to me, all this leaves her especially vulnerable.
Any advice?