It always started off small with Akutagawa.

Generally being more grumpy, headaches, complaints of dysphoria.

Atsushi knew all the symptoms of a period, having lived with Akutagawa long enough that he learned how to help.

Akutagawa’s period had been inconsistent ever since he started Testosterone. And with that, threw off Atsushi’s ability to time when it's coming- leading to situations like this.

First mistake, he had woken up and gone to work earlier than usual.

Second mistake, he didn't bring anything home with him. No snacks, no treats, nothing. It's not like he could telepathically know if Akutagawa wanted something.

This all culminated with Akutagawa being all clingy, practically dragging Atsushi by his tie to bed before he could even fully step out of his shoes.

“Ok! Ok! I'm cuddling- we’re cuddling." Atsushi huffed, though there was no resentment. They tangled together, his arms around Akutagawa’s waist, allowing the other to cling to him tightly. He shifted a bit closer. The least he could do right now was comfort him through cramps. “If you keep smothering me I can't go get you anything, y’know?”