"Why'd you have to use tongue?"

Castiel is unsure about sexual activities. The pizza man didn't explain how to cope with Dean Winchester.

Castiel is complaining to Dean about what the pizza man did NOT do

dean tries to make a move on cas, cas does not understand

Dean trying a corny pickup line on Cas... Cas doesn't understand.

Dean asking Cas if it hurt when he fell from heaven. Cas is quite honest about his answer.

dean hits on cas

Dean asking Cas if he wants a drink, but Cas doesn't require hydration.

cas and dean are perplexed by a glass of water