Jerk-In-Law

Depending on the level of sexual harassment that you're talking about, could she have legal recourse? Police report, restraining order?

I'm guessing that this girl isn't willing to cut her sister out of her life, since you mention that she loves her. Is she willing to tell the sister that she will only see her if the brother-in-law isn't around?

If he's just an insensitive jerk, he can probably be reasoned with. It may require a man to set him straight -- some people will ignore what a woman says but take what a man says much more seriously. I've run into more than a few in my life. It's stupid, but true. Deal with him by laying down the facts -- that this is not okay, that he's genuinely hurting his sister in law, and that he should act like more of a gentleman. Not violently, not even aggressively, just straight-up, one-on-one, and man-to-man. This approach can work wonders, especially if delivered over a few beers.

But... if he's actually a truly abusive person, it's vital that your GF start trying to get her sister out of that relationship. Any kind of confrontation could easily lead to him being the one to cut his wife out of her sister's life, isolating her wife and making his abusive behavior harder to stop.

I know that question didn't mention anything about abuse, but these people follow a pattern, and that kind sexual harassment is a part of it. The sister-in-law being unwilling to talk to him about it is another bad sign; she may be afraid of him, or overly submissive to him (and not in the fun way).

As I said, he may just be an insensitive jerk, and amenable to reason if it's delivered by a fellow man who he's compelled to respect in that manly, brotherhood-of-guys way. I truly hope that's the case.

- But... if he's actually a truly abusive person, it's vital that your GF start trying to get her sister out of that relationship. Any kind of confrontation could easily lead to him being the one to cut his wife out of her sister's life, isolating her wife and making his abusive behavior harder to stop.

I know that question didn't mention anything about abuse, but these people follow a pattern, and that kind sexual harassment is a part of it. The sister-in-law being unwilling to talk to him about it is another bad sign; she may be afraid of him, or overly submissive to him (and not in the fun way). -

In this, I agree whole-heartedly. In fact, I think it may go a little deeper (scary-deep).

I also think brother-in-law is looking to fulfill a sisters fantasy, AND he has his wife at least partially on-board. Or at least not going to be of any help to her own sister.

If the two sisters can't come to a mutual agreement, then that relationship has most likely already been abandoned by the married sister long ago, and she just didn't tell anyone. I'm sorry to have to say it, but it's true. After a certain stage in life, many siblings go their separate ways.

Otherwise, the only way to straighten this guy out without straining the bonds of sisterhood is to find a trusted third-party to break his legs semi-annually. Not advisable, but effective (sort of - he would then probably become a physically abusive alcoholic against his wife, if he isn't already).

Her sister, who she loves, is no help at all and just tells her to "go along with it" so she won't have to deal with any conflict with her jerk of a husband.

Warning, Will Robinson! Danger! Danger!

I'm with the other posters. There is something seriously wrong with the relationship that this schmuck has with his wife.

In addition to the other suggestions, I'd say the girlfriend of the questioner should try to arrange for a private lunch (or other one-on-one meeting) with her sister and try to find out whether her husband is emotionally and/or physically abusing her -- it would not surprise me in the least if he were. If he is, that woman needs some serious counseling, lots of emotional support, and probably a good divorce attorney.

I don't think I'm reading too much into this. This is not a healthy relationship.

-No matter how many times she yells, hits, or kicks him in the nuts, he doesn't let up.-

I'm just worried that this is meant literally. If he is physically touching her during these encounters, that's not harassment. That's assault. If your girlfriend thinks this is just simple harassment, then she may have some deep, DEEP routed issues in her own past, like an abusive elder.

If you choose to make a commitment of this relationship, be ready for some serious s%#t.