Is it legal to move in with an 18 year old when you're a minor?

i think that since you are only moving in thats fine. its not like your brother is taking custody of you, your parents still have that until you turn 18. my sis is out living with two friends, they are all 18, but i almost moved out with them when i was 17 and there was no problem. as long as you dont get into anything crazy, then youre fine.

disclaimer: i have no legal idea if im telling the truth, im going off common sense here, so i could be wrong... but i dont think i am.