Bleeh. It's usually best to just shut the forget up when your dad is talking to you. At least, that's what I do.
I usually try to ignore my sister, since my situation used to be the same as yours. (sister tells parents you get in trouble) Although, I guess I kind of deserve to get in trouble, she just loving pushed me off the edge sometimes. (She broke my damn door, so I gave her a bloody nose and threw her down the stairs.) Nowadays, however, the tables have turned. Me and her are on good terms, luckily for her, but if we ever got in a tussle my parents would trust my judgement over hers.
My best advice to you is to learn to just ignore everything around you, that skill has helped me in god knows how many situations.