The houses they built in those days were left hollow underneath and they called the spaces cellars. They kept odd things in them: old clothes, shoes, jewels, beautiful glass, stiff wedding gowns and albums, bits of furniture with difficult names, and quite often some people they dearly loved. When this was the case, they kissed them hard and locked them in, and then quickly bricked up the doors so they couldn’t open them and leave.
Since there wasn't an exit and the walls held tight, the old loves lasted well and everyone took them for immortal.