itsk shotakuna succubus AU inspired by a doujinshi I read a while back. Basically, shotakuna visits Yuuji every night to feed off the arousal he feels during his horny dreams until one day he gets curious about how big Yuuji's cock could be. He is a horny demon after all!

Sukuna had chosen Yuuji as his main food source due to the man's good health and fitness but beyond that he considers him a dumb and annoying human, that doesn't stop him from breaking the rule of not having sex with humans.

Sukuna thought he was cautious when one night he finally succumbed to his desires and began bouncing on the human's incredibly large and thick cock, only to be startled when he felt hands on his waist and began to be drilled in the air.

Yuuji had woken up from his induced sleep but when he saw the image in front of him he thought he was still dreaming; On his lap was a pink haired boy shyly bouncing on his cock 'since when had he become a shotacon? well if this was a dream it didn't really matter, besides the boy was adorable'

Sukuna couldn't think clearly as he felt that cock drilling his prostate but that didn't stop him from insulting and yelling at the human to stop, it was forbidden for a human to ejaculate inside a succubus, if he did, the demon would be linked to the human and trapped in the human world forever.

Yuuji stopped, after cumming for the fifth time inside the boy that is. In the morning was when he really realized that everything had been real when the demon woke him up hitting him with his adorable fists, yelling that because of him he wouldn't be able to return to the underworld.

Yuuji felt bad but, now he would have an adorable succubu by his side forever? thinking about it he didn't feel so guilty.