Winning - even at something that wasn't really a race - makes Catherine playful.

Nick's not a kid, and certainly isn't Catherine's but he still ducks his head and laughs when she runs her fingers through his hair.

She talks the whole way back to the lab, and he grins at the purr in her voice when she talks cars. She slings an arm around his shoulders walking inside. Easy, comfortable warmth with her hip brushing his every step. This is Catherine. She doesn't really notice and he's used to it.

He wishes it could be this easy with Grissom.