When I was 6 yo, my mom had a set of twins, but they had some birth defects. One just had a clubbed foot, but the other had been born w/o part of his intestines. From birth until about age 1, he had a colostomy. After that he had multiple surgeries to fix the problem, but was fecally incontinent until age 10.
In addition to his physical abnormality, he also had behavioral problems. He has ADHD (Attention Deficit Hyperactivity Disorder) and Oppositional Defiance Disorder (ODD). His ADHD is "controlled" through medication, although he still makes bad judgments and has a hard time thinking through his actions.
The boys are college age now. The twin with the behavioral problems is a bully and can't seem to take accountability for his actions. The two were enrolled in classes together, but he just blew it off and copied off the other twin. They also work together, and that's hard, b/c the place they work has this policy that everyone finishes together and leaves together. Well, the problem twin finished, and his trainer tells him to leave, so instead of talking to the manager to see what else he could do, he just left. Now, he doesn't have a car, so he uses his cell to call mom. When mom arrives, she asks where his brother is. So the problem twin decides he's going to force the other one to go. He started knocking on the drive-thru window, and calling him on his cell, just being very disruptive in general. His brother had to ignore him to finish his work, and when they left he told the other one that the manager was really mad at him.
Long story short, the (I'll call him "problem twin' b/c i don't want to use his real name) is sabotaging his brother. He can't get anything done w/o his brother acting like a maniac and trying to manipulate him so he can just scrape by with the bare minimum. It's a shame he's doing this, and I hate to see my brother suffer thru this.