YIKES. NO. NONONONONO. Mokuba not only spins to face away from Yuugi, but he also covers his eyes, as if somehow some guy's state of undress is going to reflect off of the walls and end up in his face.

"I'm not looking! Just don't fall off the couch, I'm not picking you up if you're naked!"

They're friends. They aren't THAT much of friends, buddy.