Dean was probably going to do more than that, but as always, Lucifer wasn't as concerned with his reaction as he was Sam's.

.. even if bating Dean was something of an amusing pastime for him.

Unlike some of his younger siblings, Lucifer wasn't ignorant when it came to matters like sex. He cupped Sam's cheek as he returned the kiss, drawing him in closer. His hair was exactly as soft and thick as it looked and he carded his fingers through it, deepening the kiss.