More Ettiquette hell madness

"First, let me say how entertaining and informative your website is. Some of your readers may wonder if the more outrageous stories are true but I sure don't. I know how amazingly rude people can be, because the following story is absolutely true.
Several years ago my brother was hospitalized for several weeks with a serious illness. His condition was so grave he was on a respirator for a time. My entire family flew to the city where he lived to be with him, staying in a nearby hotel and spending our days at the hospital. Because all his siblings have jobs and families and live far away, and because our parents are both still employed and live far away as well, we couldn't all stay with him the entire time, but took turns flying in and out and being with him. Of course, his own wife lived in the same town, in the same house, which my brother owned (he bought it before their marriage). But my horrible sister-in-law only came to see my brother, her husband, in the hospital ONCE, on the day he was admitted. She then declared, through her tears, that it was "just too difficult to see him like this" and disappeared! He was in the hospital literally for months, and she was MIA. We called and asked her to come, but she refused. Then my parents when over to their house (my brother's house) to demand that she go see him, but she refused to their faces. They also noticed that the house was filthy and the living room full of overflowing ashtrays and empty beer cans.
Once it was clear Brother was getting better, my parents (who were with him at the time) had to go home. Another brother was flying in a couple days later, but Ill Brother recovered so quickly (once he was recovering) that he ended up being discharged on a day when no family was in town. So he called his wife for a ride home. She said she was going to lunch with some friends, but she'd be by to pick him up when they got done, and he should just wait in the lobby of the hospital! Weak and exhausted, he then called a taxi to take him home. When he arrived, he found the house filthy just as my parents had seen, but also found that in his absence SHE HAD MOVED ANOTHER MAN INTO HIS HOUSE! Shaving stuff in the bathroom, clothes in the closet and on the floor in the master bedroom, the whole nine yards. Not surprisingly, shortly thereafter Brother got a divorce. This made his physical recovery more difficult because, no matter how richly deserved, a divorce is almost always a painful process. Throughout the divorce proceedings, my ex-SIL kept calling him and telling him how much she loved him and how sorry she was, but some things you just can't forgive. Brother is now married to a wonderful woman who is amazed at how awful his first wife was."