His plant parts make direct sunlight pleasant in a way it wouldn't have been otherwise, so Steven stays where he is for the moment, though he turns to follow Tamaki's position. He starts looking a little bit embarrassed as he's forced to contemplate his answer to that.

"I just... decided to be sad on the outside, instead of hiding it on the inside. Because keeping it on the inside... wasn't really helping anymore."

He rubs his arm, staring at the ground.

"Maybe that sounds dumb."