You are correct, but most people being abused can gain confidence by having someone "love" them. Having a relationship to jump into is often the push they need to finally get away. Once they're out they realize their strength and a breakup is easier. It isn't fair for the "hero", but in some cases it saves a life.

In dream world, you'd get her away from both at once. In reality, the hideous truth is that it's simply not going to happen that way. People with abusers don't have the self esteem to so easily become independent. However, the HUGE thing is that she's interested in someone else, which means she's not TOTALLY specifically latched onto her abuser. You wanna be smart about it and do what's best? Let her leave her abuser first, while she's doing that, investigate the catfisher more and ONCE SHE'S LEFT HER ABUSER spring evidence. Sorry for the double post, but I only saw you replied after I posted the original, can't delete and wanted the best chance of you seeing this

I like 26's idea, but there's one thing that concerns me about it. Basically, the intention would be to use the catfish as the emotional rope by which your sister climbs out of her situation, right? Problem is, can you trust this rope? The only thing you know about that person is that they're lying about who they are. Not the best resume to have when deciding whether to trust someone with your sister's safety and emotional state. Worst case, the abusive husband could be the catfish (it might be a stretch, but I bring it up to emphasize how badly trusting the catfish could go). Find out who the catfish is before making a plan to use their position in your sister's life to help her. Good luck

She sure knows how to pick 'em.

Or, how about unlike what these other posters have mentioned, you DON'T manipulate her and run aspects of her life from the sidelines. Honestly, showing the husband proof of her infedelity might make them divorce. Or not, again, it's not your place. Maybe act like a rational adult, sit her down and present all of the facts, data, and your honest opinion of the matter. Make a whole day of it of you need to. Just don't manipulate her, I'm sure her husband does that to her enough, and the goal is to get her to move on, not possibly damage the trust she has in a person whom can save her from the hole she has dug herself.

yeah, tell the abusive husband he's being cheated on... great idea!

adultery is against the law so

#29 Who here said anything that would make you assume they're advocating for the OP to manipulate and run her sister's life from the sidelines? What they are suggesting here is to SUPPORT her, to help her get out of her situation, which sometimes means taking things one step at a time. You clearly don't know how abusive situations work, the victim often doesn't realize that they're being abused, they think they deserve it, they can't leave because of financial or other support needs, or they simply won't leave because of psychological manipulation where the abuser convinces them that they aren't allowed to leave, or that no on would want them if they do. These situations are delicate, so if the OP were to lay down all the facts and the truth of the situation, it risks her going back to her abusive husband, especially since she is an abuse victim, if she finds out her bf is a scumbag, she might think her husband is right, that no one wants her and she deserves to be with him. The OP wouldn't be manipulating her sister by helping her get away from her husband, then telling her about her bf behavior, she would be delaying the full truth until her sister is in a more stable position, getting her out of the worse situation before she tells her about the bad, but less worse, one. Also, no, adultery is not usually illegal. I haven't checked in a while, but I knew some US states have, or did have, adultery laws, but they aren't enforced. Some conservative countries do have these laws too I guess. Either way though, I don't agree with cheating, (although my feelings towards situations like this, where abuse is involved are a little different) but making it illegal is ridiculous and too far.

she needs to leave her husband and forget about her "boyfriend". You need to tell her, but you need to show her no man is needed to move on. All she needs is a supportive family for her and her kids sake. I've grown up with my parents having a terrible relationship and it's led to some.... rather scarring events. She needs to leave ASAP

Except it's not... It can be used as grounds for getting a divorce with an extremely favorable distribution of assets favoring the partner who was cheated on, but it's also not going to make the police come after you. Another thing to consider with this idea is that it could mean that she's unable to retain custody of the kids favorably (she might get a weekend here and there, but probably not full custody... Unless his abuse is provable). If his abuse isn't provable, he could have the opportunity to really mess the kids up before he's found out. I dunno what the best solution is.

I'd show her the catfishing evidence you have first. Once she realizes you have her best interests in mind and that you were right, she'll be more likely to listen to what you have to say about her husband. But please don't use the manipulative catfisher as any sort of solution, especially since you don't know who it is. That'll bite you later, especially if she gets lonely and goes back to her abusive husband later since the only reason she left him in the first place was because of this catfisher.