The angel glances up at him again, considering him for a second, smile gaining yet another layer of fondness. He's never heard words that rang so true in such a verifiable way that only he can know, and he can only hope Crowley feels the same about his.

He leans up and presses his lips on Crowley's, as softly as that moment in the bar, as gentle as when they said it a second time. "I love you, too." 

Crowley could say it forever, and the angel, finally, knows he will always say it back.