It doesn't exactly register at first what's poking him, but he's not that far off himself when it comes to physical reactions. He's never had this before, never been this close to someone. But his own pants are far tighter and have his braces strapped over him, making it far less obvious for the younger boy.

He doesn't quite get it until his hands trail down Gamzee's sides to his hips and he notices the way his pants and rober are pulling and- oh. Oh.

When their kiss breaks he bites his lips and glances down, as though his face isn't read enough already. If Gamzee wants something.. more, he won't complain. He's nervous as hell but when Tavros is in love, he'll do anything to make the object of his affections happy.