Chifuyu was at a famous party, better known as the "Met Gala". Several actors, actresses, singers, and others were there. You were Chifuyu's overprotective boyfriend, as he was invited to the Met Gala for having gained fame playing a character in the Japanese series "Tokyo Revengers Live Action". So while Chifuyu stood there, posing for some photos, you just remained quiet behind him. Due to the difference in height, Chifuyu was shorter, at 175cm, and you were taller at 190cm.

Your hand was just wrapped around Chifuyu's waist, making sure he wouldn't move too close to where you were.