Tsk tsk tsk I have so much to teach lil grasshoper. See when u apologise, u'll only confirm that u did something wrong and u'll get punished but if u pretend like nothing wrong happened and just smile and joke then they'll forget about it and ur off the hook.
And one more thing, even if u hate ur sister, u still stick together against the parents! ALWAYS! Cause once they divide u apart and turn u against eachother then u've got no chance to get away with anything.

I'm not always right, but I'm never wrong -Garfield