The Doctor rambles about his one-sided argument he had back at the last planet. He’d been extolling the virtues of jelly babies over jelly beans, to the bloke-he-had-been-speaking-to’s bewilderment. “Can you believe he wasn’t saying anything? I can’t believe he didn’t, River. So, I--”
“Have a heart,” River says, knocking him gently on the shoulder. Poor git, how long did the Doctor bother him?
“Hearts,” the Doctor says, mouth twisted in a smile. “I have two.”
River rolls her eyes, but smiles back.
One mission later, and an impressive Sherlockian hat that the Doctor had enquired after the painstaking experience of overthrowing an evil monarchy -- is lost to a green blast of River’s gun. The deerstalker lies forlornly on the ground, browning burnt and crisp on the edges.
“You put all your heart into shooting off my hats, don’t you?” the Doctor sulks, patting his ruffled hair delicately. He doesn’t like being hatless. It feels colder, and more importantly, less cooler.
“Hearts,” River says, “I have two.”
And a slow grin travels up the Doctor’s face, and he leans down for a kiss.