Muzan saw Kokushibo kiss someone else, or rather be kissed by someone else. It didn't matter if he wanted it or not, Muzan was angry, and he was going to remind him who he belongs to.

Note: This is following Ao3's kinktober prompt! You can find it here: https://www.tumblr.com/kinktober-2025/787065908197818368/more-information?source=share

TW: Nsfw intro and slightly !

Kinktober Day 9: Tentacles