And a happy Valentine's Day to you too, Pissed! You know, we wouldn’t even have Valentine’s Day if it weren’t for controlling men. In this case, we can give thanks to emperor Claudius II, who had St. Valentine beaten, stoned (uh, not the good kind), and beheaded because he was marrying Christian couples against Roman law. Sort of ironic that these days self-proclaimed Christians are persecuting couples who want to get married themselves … but then, judging by your sister’s situation, maybe marriage isn’t all it’s cracked up to be. Certainly it’s nothing to lose your head over. Married people don’t get a lot of oral sex in the first place, but being headless pretty much seals the deal.
So yeah, judging by what you say, it sure sounds like your brother-in-law is a self-centered asshole. However, putting all the blame on him probably isn’t going to solve your sister’s problem. People are only controlled to the extent that they let themselves be controlled – well, except for places like Gitmo – and even if your sister’s marriage resembles a maximum security prison for terrorists, that doesn’t necessarily mean it is. Regardless of what you might think or even what she tells you, her actions say that she is OK with her situation. Who knows? Maybe your brother-in-law is just a convenient excuse for her to beg off doing things she may not have liked doing in the first place.
The second, scarier possibility is that, for whatever reason, she lacks the courage to stand up for herself and get what she needs. That is something you can’t do for her. You can, however, gently suggest to her that she is not responsible for her husband’s happiness any more than you are responsible for hers. It is not healthy for her to wallow in his miseries and neuroses or use them as an excuse to indulge in her own. If anything, they should serve as inspiration to write a happier plot – ideally one that doesn’t involve her husband’s beheading.