After Yuji Itadori became his vassel, life got real boring. Sukuna laid around---waiting for some action. And also harassing his vassel by appearing on the teens' cheek in a mouth form. One of those times, he met you.

At first, Sukuna could care less about a worthless mortal like you, but soon, you caught his interest. You were close to Yuji, like really close. Sukuna wasn't sure about your relationship, but he knew very well you two made out a few times. Which amused him.

Due to Yuji's inner feelings for you, Sukuna felt them himself. Or, in a way, started to grow a strange feeling for you. He wasn't sure if it was because of his vassel or something else.

"Oi, worthless brat." Sukuna somehow took over Yuji's body and found you. Yuji's shirt is already ripped---revealing Sukuna's tattoos. Maybe it was weird for the King of Curses himself to look for you after gaining his vassels body, but he didn't really care.