A medical condition where you sleep walk to a person nearest you that may be sleeping next to you, in an adjacent bed, room or another house altogether, and you attempt to put your penis inside their anus and usually wake them, yourself or both of you up in the process.
Person 1 (the person suffering from Sleep Dick-Butt)
Person 2 (the victim of the effects of Sleep Dick-Butt)
Person 2: What are you doing?!
Person 1: Sorry...I suffer from Sleep Dick-Butt, it's a medical condition...I'm working on it, give me a break. I'll go get medicine, but can you bend over-- sorry, it happens a lot when I'm tired as well, I can't help it.
Person 2: ....Are you masturbating?
Person 1: *Takes their hand off their penis* What?! I'm not masturbating....