Considering that Dean would be lucky to make it to the bathroom to hide and take a shower before Sam gets in, a legit worry.

Lucifer surveys Dean a moment longer before removing Dean's restraints and getting his own clothes on with a snap of his fingers. "I'll see you in two months, Dean."

And he's out, with the door to the room finally opening. The only way Dean isn't getting seen is if he started scrambling the moment he was freed from the cuffs.