When you've been flirting with Castiel for the past half hour until you leave the motel room to get some food and the angel tilts his head confused about what had just happened.
"I am confused, why was (Y/N) acting like that Dean?"
"You really are oblivious Cas, (Y/N) likes you."
"Oh okay... What do you mean like?"
"What do you- Nevermind, (she/he/they) will tell you eventually."