When it comes down to it, this poem is about trying to get a woman into bed. We would hate to be simplistic and take away from all the rhetorical fireworks that Donne sets off in order to distract us, but sometimes you've got to call a spade a spade. The speaker never comes out and says he wants to have sex with the woman, but that's precisely what a "marriage bed" is for. He doesn't want to scare her off by reminding her of the blunt truth that having sex with him would, in fact, result in a loss of chastity.
- Line 2: You can get away with so much in a poem by simply using vague language. The phrase "that which" has very sexual overtones. We know which that he's talking about.
- Line 7: The "enjoyment" of the flea is a pun. The flea literally "enjoys" her blood, but to the speaker, it also "enjoys" her in the erotic way that he would like to "enjoy" her.
- Line 25: "False fears" is an example of alliteration that highlights her concern about the loss of chastity.
- Lines 26-27: "Yield'st" is a small pun. He wants her to "yield" to the (twisted!) logic of his argument, but he also wants her to "yield" to him...in bed. Yes, we're serious. Also, he uses a simile that compares the preservation of her life when the flea dies to the preservation of her honor after she has given in to him.