A smile blooms slowly and brightly on Crowley's face, shining with a (not literal) radiance only seen a few times in their long, long history. The first was six thousand years ago, when he felt the first drops of rain and laughed with delight at the new sensation. Crowley has always had a gift for delight. It's been dampened (also not literally), eroded by years of Heaven's indifference and his own doubts turned to cynicism, but it's never left him.

It's hardly ever shown as openly as this, however, even to Zira.

"Thank you." He laughs a little in wonder and amazement, squeezing Zira's hands in his, then tilts his head curiously. "What's that face for?" Despite the question he sounds relieved almost to the point of giddiness.