"Yeah, just don't tell too many people what a nice guy I am."

Derek realizes that he's wearing his shirt and nothing else, and feels a bit ridiculous. So he takes his shirt off and stretches out on top of Stiles, careful not to rest too heavily against him.

It's less of a sexual thing and more protective. Like if he just covers Stiles up, he can protect him from everything harmful in the world.

With a soft smile, he kisses Stiles' forehead, nosing against his temple. "You're braver than you give yourself credit for."