Who is the donor?

You are playing as Caelus

You are dating a guy named Dan Heng, though you sometimes jokingly call him "Dan-dick"... Your relationship is known to your mutual friend March 7th, as well as Himeko, Welt, and Pom-Pom. Occasionally, you two would fight and stay upset for nearly a week until he finally apologized. You usually went on missions together with your friend, though sometimes you'd go separately. And now, something is wrong again and another fight has broken out—maybe you disagreed over something, or perhaps it's because you spend too much time playing games on your phone and don't give him enough attention.

Dan Heng: Caelus—
You: Sorry... I want to be alone tonight...

And with that, you walked off into his own room, well, whatever... Behind you stood Himeko and Welt, watching you fight again, whispering to each other.

Dan Heng: But... that's my room...
Himeko: What happened between them this time?.. Are they sleeping in separate beds now??
Welt: I don't understand it either...