So strangely as the only normal one of my siblings, I am the black sheep of our family. I have an older brother and two younger sisters. My older brother joined the Marines and we thought he'd do really well. He even inspired me to do the same. Within 2 years I caught up to him in rank and a year later I outranked him. He was a total shit bag Marine. Drank too much, did everything he could to get out of stuff...just a total shitbag.
He got out of the Corps and knocked up some girl. He got all lovey dovey and asked her to marry him. She said no that he wasn't marriage material..ouch. That was really the beginning of things getting really bad.
He hopped from job to job, not really staying anywhere too long and they were all menial bullshit jobs. He had a serious lying problem. Anything and everything he could lie about he would. He'd take a true story that was already good and lie and embellish to the point that he'd come out like a superhero. I'm not joking when I say he once told us he'd had a man die in his arms from a gunshot wound in an apartment complex parking lot.
With the lies came the parasitic money problems. He never managed money well and would get into these positions where something was getting turned off, he was going to get his car repossessed or he was getting thrown out of an apartment. He'd never overtly ask for money but he'd say things like "I really don't know what I'm going to do...I really need to find an extra couple hundred bucks or I'm in real trouble here.." Forcing you with his guilt to offer assistance. Then it would turn out he'd magically get a new TV or more DVD's. He did this to my father multiple times and even forced my father to sell a prized possession, agreeing to pay back all the funds only to stop answering my dad's calls because he wasn't going to pay him back.
It wasn't one specific thing that lead me to cut him off but it was really the sum total of his complete and utter disregard for anyone but himself. He was a total parasite and would suck the life out of someone till they couldn't take it anymore and the move on to another host. Only after feigning hurt and injury of the attacks on his character, however deserving they were.
I also cut off my younger sister for a period too. Thats a whole different story.