The Christmas Curse by Catherine Lievens

Calyx didn’t mean to curse his brothers—really, he didn’t.

After their mother died, their family scattered on bad terms, and Calyx lost his adopted brothers. It’s not too much to want them to come home for Christmas, is it? It’s not Calyx’s fault that, in his haste and grief, he cast a curse that would kill them if they didn’t. Besides, he managed to change the curse to something non-lethal.
Griffith didn’t want to leave the house where he grew up, and he certainly didn’t want to leave Calyx, but his feelings were getting out of control. He needed space from Calyx to get over them, and he got that space.
He also got an expanding Christmas-colored tattoo on his chest.
Griffith knows Calyx meant well when he cast the curse, and while he’s happy to go home and see him, not all of their brothers will be. The problem is that they don’t have a choice if they don’t want to end up permanently colored in green, white, and red from head to toe.