What we did: love. We did not spend our days gazing into each other's eyes. We did that gazing when we made love or when one of us was in trouble, but most of the time our gazes met and entwined as they looked at a third thing. Third things are essential to marriages, objects or practices or habits or arts or institutions or games or human beings that provide a site of joint rapture or contentment. Each member of a couple is separate; the two come together in double attention. Lovemaking is not a third thing but two-in-one. John Keats can be a third thing, or the Boston Symphony Orchestra, or Dutch interiors, or Monopoly. For many couples, children are a third thing. Jane and I had no children of our own; we had our cats and dog to fuss and exclaim over—and later my five grandchildren from an earlier marriage. We had our summer afternoons at the pond, which for ten years made a third thing. After naps we loaded up books and blankets and walked across Route 4 and the old railroad to the steep slippery bank that led down to our private beach on Eagle Pond. Soft moss underfoot sent little red flowers up. Ghost birches leaned over water with wild strawberry plants growing under them. Over our heads white pines reared high, and oaks that warned us of summer's end late in August by dropping green metallic acorns. Sometimes a mink scooted among ferns. After we acquired Gus he joined the pond ecstasy, chewing on stones. Jane dozed in the sun as I sat in the shade reading and occasionally taking a note in a blank book. From time to time we swam and dried in the heat. Then, one summer, leakage from the Danbury landfill turned the pond orange. It stank. The water was not hazardous but it was ruined. A few years later the pond came back but we seldom returned to our afternoons there. Sometimes you lose a third thing.
-- Donald Hall via Poetry Foundation (h/t @Kcecelia)