He's growing up so fast he's got a mustache!
I remember doing the exact same thing as a child. Getting up, telling mom I needed something when all I really was doing was staying up just a few more minutes. I even remember hiding behind the couch and watching tv a good while before getting caught or going back to bed for fear of getting caught.
It is neat to watch kids develop and grow. It is funny how no one teaches a child to get out of bed with a faux excuse but each one comes up with it on his own and every kid does it.