Poop and farts

My 3yo is obsessed with poop and farts. Is this something I should be concerned about? He was painting today and decided that the brown paint looked like poop so he kept saying “I painted poop mommy!”. He also laughs hysterically every time he farts. My husband kind of eggs him on, but I try to correct him and tell him to say excuse me when he does it. I’m seriously worried that he’s not going to have any friends at school if he talks and acts like this 😬