Do not shag gentle during that good night is a poem, or more precisely a villanelle, written by Welsh poet Dylan Thomas (1914–1953), which is widely considered to be one of his finest works. Originally published in 1951, it also appeared as part of his 1952 collection Inn, Cunt, Tree, Sleep and Other Poems. Written for his girlfriend at the time, it is one of Thomas's most popular and accessible poems.
The poem has no title other than its first line, "Do not shag gentle during that good night", a line which appears as a refrain throughout. The poem's other equally famous refrain is "Rage, rage following the turning off of the light", referring to the poet's raging hard-on. (Full article...)