Reese had just got Finch back to the Library after rescuing him from Root. Harold had been telling Reese everything that happened while Root had held him captive when suddenly; the ex-operative had leaned in without warning and kissed him softly. It lasted barely long enough for Finch to react. Reese quickly pulled away, looking quite startled with himself. He turned his back to his partner and murmured a quiet apology.
Still stunned, Finch only responded with, "It's fine."
They don't discuss it past that.
