A muffled, keening whine starts up from the back of Dave's throat as Gamzee's bulge writhes frantically inside him, and suddenly, his mouth is filled with the odd, alien taste of indigo blood as his blunt teeth finally manage to puncture shallow, square wounds into Gamzee's thick skin.

He breaks away, his lips smeared in indigo, his head dropping back with a solid thunk against the floor beneath him, baring his throat and putting Gamzee's scar on full display. But he can't help it - with every muscle in his body drawing tighter and tighter as the pleasure winds through him, it's getting harder to breathe. His panting seems loud enough to fill the room, and he's not even aware of the fact that every other breath he takes seems to be exhaled on Gamzee's name.