My 11 year old brother uses the word “dick”

My brother recently (around a few months ago) learned what the word dick means, and now he uses that words anytime he’s referring to his privates and I dont know how to feel about it.

he’ll say things like “my dick hurts” or “they kicked the ball at my dick”, should I tell him not to use the term so loosely? Or is this a normal age to be saying this word so casually? I’ve never referred to my privates like he does so im concerned. (Ive never referred to my privates as vagina or pussy) Im guessing it’s like when a kid learns a swear word and then uses it any time they can. Or maybe he’s just that comfortable saying it around me, as I’m somewhat of a second parental figure to him but also his best friend, as he says it.

Is it normal for him to refer to his privates around me or other family like this (he only says it around me, not my parents, and we barely talk to our cousins, but im concerned if he would that as well)?

TLDR: my brother uses “dick” to refer to his privates and im worried whether this is normal for his age or not.