Kaiba lets out a shuddering breath, then tries to sit up, slowly. He doesn't want to be on Yuugi's lap anymore, although he still feels out of sorts. Not being feverish does help with that, but he's still not very strong. It takes him longer than he'd like, but he does manage to roll of of Yuugi and prop himself up onto one elbow.

More to the point...

Why aren't you wearing a shirt?

Somehow, his facial expression makes that seem accusatory.