“The Flea” is a poem by the English poet John Donne, most likely written in the 1590s. In “The Flea,” the speaker tries to seduce his mistress with a surprising (and potentially gross) extended metaphor: both he and she have been bitten by the same flea, meaning their separate blood now mingles inside the flea’s body. Having sex is no different, the speaker argues, and no more dishonorable. His mistress should therefore yield to him. Though the metaphor is intentionally pretty crude, maybe even juvenile, the speaker infuses the poem with religious undertones: the union of speaker and mistress in the flea is like the Holy Trinity. In this way, the poem is both serious and silly, elegant and vulgar. It is as much a display of wit and erudition as a serious attempt to seduce the mistress.