In line at the grocery store I hear the faint sounds of a duet, and for a split-second I think it’s music playing over the sound system. But then I realize it’s a couple standing in front of me in line: they’re quietly singing together. They’re in their early thirties, and they’re harmonizing an American songbook-sounding number I don’t recognize. Every so often the man leans over and kisses the woman. The wait attenuates, and the longer I stand behind this flirtatious, cutesy couple, who can’t help but spur on each other’s harmonious riffing, the more I want to take my cart of groceries and wallop them both over the head with it.