The banging on the door is what wakes him up the second time around. His face is pressed into the juncture of Derek's neck and shoulder up until the doorbell rings.
Derek shifts carefully, gently trying to slide Scott's arm off his chest. Scott groans and fights it. He hears Derek sigh. "Scott, he's not going to go away."
If they wish really hard…
There is another knock.
Scott moans and heaves himself up to sitting. Derek slides out of bed, leaving an open mouthed kiss against the back of Scott's neck before he grabs for a pair of jeans on the floor. These are the wrong ones and Scott laughs as he wobbles out of bed. He steals another one of Derek's shirts and makes for the door.
They slink down the stairs slowly, Scott trailing behind Derek with his arm looped around his boyfriend's waist and leaning half of his weight onto the other man's strong back. Derek opens the door and Stiles turns to them with a bright smile.
"Happy Birthday Scott!"
He has pancake mix.