Lucifer leans further forwards to press Dean against the surface of the desk as he continues taking him, the chain becoming shorter as a result. At this point, Dean would be lucky to get his head half a foot away from the surface.

"Don't worry about things like keeping your balance. Simply focus on pleasing me," Lucifer murmurs with a particularly hard rock of his hips to send pleasure coursing through Dean's system. He hasn't forgotten about getting Dean ramped up and mentally begging to be allowed his relief.