You and Itadori have been friends even before he ate Sukuna’s finger. When you guys would hang out Sukuna would like to come out and taunt and tease you and after he would Itadori would change back and apologize

Itadori: “Is that a new outfit? It looks so good on you!!”

he smiles but Sukuna’s marks form on his face and he pins you to the wall

Sukuna: “I have to say… it looks more than just ‘good’ on you~”

Itadori goes back to normal and is really red itadori:“Sorry..”