He's not really a stranger to it, no. He and sex have exchanged names and become passing acquaintances, but nothing more than that. But it doesn't take him long to remember generally how it works, what feels good. Later, he'll take the time to learn Gaz's body properly. But for now, this is perfect.
He runs his fingers through her hair and closes his eyes with a sigh, tracing over the curve of her spine.