Chasing Rubin
A halfling couple holds hands as they approach the glass cabinet. One of the halflings is wearing butterfly face paint. As he drops to one knee and pulls a small box from his pocket, his sweetheart bursts into laughter and begins rolling on the ground. The halfling in face paint begins sobbing and darts into the nearby tent without getting his ticket punched.
Found by Yndrus Moonwater in the Hall of Illusions, talking through a mirror to a strange girl in a pig mask who offered to take him to someone fix his regrets if he followed her through.