Twosome is a tiny poem that packs a whole relationship into a few short lines. It begins with counting: one ache becomes two aches, as if pain doubles when it passes between people. The two "great beauties" are marked by the pox, a disease that scars the skin, yet the poem calls them beautiful anyway. Whatever they lack in smooth good looks, they make up for in having "one another."
The last stanza plays with the phrase "going out," which can mean dating, or simply leaving the house. The couple is both: a pair and a pair in motion, "going all about," wandering together in public. The speaker seems fond of them and a little amused, and the rhymes and echoes (one/two, had/had, going/going) give the poem a light, sing-song feel, almost like a nursery rhyme. The mood is tender and gently wry. Damage and loneliness are there, but companionship turns them into something close to pride.