Oh but he did notice, and he basks in the feelings it inspires. It doesn't occur to him to mention that he'd feel cool to the human no matter what because to him it's common knowledge and he's too busy wishing that warmth would come back, even if it verges on uncomfortable right now, instead of snuggly.

"Slime, brother, is up to filling up a troll's digestion sack good. Don't got no hunger kicking up in me most nights. Or it's got its upset on." And sometimes he would forget on purpose for the attention.

"I'd be wicked full of bitchtits mirth to get my share on of dinner with you, brother. Even put my pan all up to its fullest to remember."

And then Gokudera remarks on the state of the pile and Gamzee starts industriously (or...an attempt at industrious, anyway) push and nudge at the pile so that Gokudera can get his relax on proper. It's not the most fruitful attempt, but he does try.