can a 16 year old be a pedophile

my friend is 16 and he's really pervy around his little brother. and i mean putting his hands under his shirts while hugging them, staring at his crotch while he's sat next to him, and he shares blankets with him alot. and alot more things i dont wanna say because it makes me genuinely uncomfortable. ive asked his little brother about it (he's 9) and he just says "thats how he shows that he loves me". idk what else he does behind closed doors, ive asked his parents they don't know anything.

also last night while i was playing with his little brother he whispered to me "Fishers hands are really cold" ?? (Fisher is my friends name) and i js found it weird. i asked him aren't they always cold on his back (when he puts his hands under his shirt) and he just said it wasn't on his back and went back to his legs. its rlly fucking weird