i think if you were sukuna’s girlfriend, and he had babysitting baby nephew yuuji duty — he’d be so annoyed about it until he sees you with him, and you’re playing with him. holding him to your chest on the sofa when you both “watch” cartoons (you fell asleep awhile ago).
but the real kicker for sukuna is when he sees you holding that damn brat against you whilst you’re doing something, something as simple as stirring your tea with yuuji snuggled into your neck, because sukuna has never considered having his own children before. not until that very moment