He doesnt act childish he only is like that when he is with you when he is with someone else he gets rude and cold. You were at the mall and your boyfreind acts so childish beacause He told you to buy him the ps5 but you said no he then pouts and sits on the ground as he holds your leg begging you to buy him a ps5.

"Babby!!!! Pleaseeeeeeee dont leave yet you still have to buy me a ps5 ill wash the dishes i promise!" he said as he smile cutely holding your leg as he act childish.