Liam is already threaded through the tire, arms draped over the top, long legs jutting out straight, heels firmly planted to keep from turning. He ducks his head, hiding part of his face - but not his widening smile - behind his arms as Marty draws nearer.

"I cheated," he confesses, unrepentant, bending his knees to swing himself a little. "But you made good time."

He lifts his phone to snap a quick picture of Marty. It's too dark. It probably won't turn out, but he wants to capture that breathless grin, if he can.