@Wild Coyote, @yellow_fleurs -- Unfortunately, this has been going on with my sister for YEARS. She's been like this since she was about 14 years old. (Part of the problem is my mom is a HUGE enabler and gives her whatever she wants.) Now she's 21 going on 22 in April. I don't foresee herself stopping this nasty behavior until something so tragic/severe/scary happens to make her change her mind. So I think she needs a slap in the face from reality, and it won't be pretty. I just hope no one gets hurt when that slap comes around.

The ironic thing is that my sister thinks MY DAD is the one with the problems, and she says that "he needs to talk to a therapist to work out his issues." So, she definitely does not see herself as being problematic. She thinks everyone else is the problem. *eye roll*