Aziraphale was very well aware of the weird things Crowley could do with his tongue, thank you very much; this, however, was unexpected.
"Crowley, my dear, do you mind?" said the angel, slightly annoyed (as he was trying to read a good book). "You already tempt me enough as is. I don't need lust tempting me as well."
Crowley (who had been licking Aziraphale on the neck) grinned and looked up at his companion, yellow eyes peering from behind his sunglasses. "I invented lust, you know," he said.
Aziraphale paused for thought, then simply said: "That figures. Well, then...resume."