"I'm not moving!" he cries out, still stuck halfway out the window. He looks around the room trying to find anything that could have caused this. Or at the very least could cover it. His coat lies on the ground near the bed. He looks back at Inara again, trying to calculate if he can get there before she does something to him. At least to have something other than just his trousers on.
Finally, Mal just draws his leg in and holds his hands up in surrender. What else can he do?