"First couple times, we had a big fight at a house party and then I caught her with one of my buddies. From then on it–"

This is about how long it takes Arlo to remember that it's not just the two of them in the circle — and as open as he is about his past (penance! it's the name of the game!), he didn't mean to be open–open. In front of everybody. At a party. All at once. There's admitting to almost-but-not-really-cheating as a teenager, and there's how rumour mills fly once you admit to a cycle of mutual infidelity between yourself and a former spouse.

"Everybody knew," he ends simply, and downs the rest of his drink.