Just a little backstory as always my sister, her boyfriend along with me and my boyfriend  live together with my parents. My sister (when her boyfriend just moved in with her before mine moved in) remarked that we would be a perfect couple because we're both skinny (she is heavily overweight) . I started being cold towards him. When my boyfriend moved in I had issues with her walking in the room in front of my boyfriend in just her underwear and too small shirts that showed her well endowedness. I mentioned this to her boyfriend as I have a severe anxiety problem along with other issues and have trouble confronting people. He said he would deal with it she continued to do the same behavior claiming that "she didn't care because she loved her body and what we thought didn't matter to her" I'm speechless at this point. She hardly does anything around the house just sleeps all day and then will wash a dish or so and say she did the dishes or say she cleaned the room I did to our father telling him I sleep all day even though people living here vouch for me. She once bought a bottle of wine for thanksgiving with her boyfriends money and then was upset it was smaller than she remembered and then try to tell my dad I drank her whole bottle of wine and replaced it with a smaller bottle. (mind you I can't buy I'm underage for alcohol and me and my boyfriend did not have a penny to our name at this point in time) she has also taken several of mine and my boyfriends shirts or hoodies and worn them stretching them out  swearing they're hers or her boyfriends, I typically get two sizes up (I fit into a size s) because of reasons and my mother and family know this my mom bought me an extremely cute outfit in light colors to help "boost my mood" the shirt was a xxxl, my sister constantly grabs the shirt and says it must be hers because it's her size, we will have that argument every time she sees the shirt. Theres more but this is ridiculously long; My sisters boyfriend has a dog, I have a work in progress to potty train puppy, the family has two dogs. My dog was locked in the kitchen with me as I was cooking, my brother went in my room to find their dog in my room ears down and poop in my room bigger than my dogs and smaller than the families dogs. My boyfriend politely asked her to clean it up, She starts yelling at him, im in the kitchen with a sharp knife and I happen to have a sensory issue so loud noises and stuff can cause issues I ask for them to tone it down, they get louder at this point I proceed to almost cut my finger so I match in there mad and find out what's going on, I ask her to clean up the mess since we clean up our dogs mess and have cleaned up hers enough, she starts called me a bitch and a bunch of other stuff I go off since I'm back in the kitchen giving it right back to her my boyfriend and brother get scared she's gonna come hit me so they go wake up the boyfriend. It's kinda fuzzy from there but the boyfriend came down later and said aggressively "don't worry we'll be gone by the first" 



TL:DR- sister has no respect for boundaries and is so painfully lazy she almost got violent to get out of cleaning dog shit, and I want to cut her off even though my father does not; Am I the asshole?