This fairly comical poem incorporates an extended metaphor of a flea, which holds both his and his lover’s blood, as an argument for them to enjoy a physical side to their love. Here there is no reference to the cerebral dimension to their relationship as with The Extasie, but it is perhaps implied given that they indeed have had a relationship without sex up until this point. Although the logic is dubious, the narrator’s manipulation of the metaphor is intricate and effective – he uses the constant comparison with flea as a constant with which he shifts the argument as if to answer the replies of the partner, whose side of the argument we are unable to hear.

The tripartite argument progresses throughout the three stanzas, with each stanza introducing a somewhat new element to the argument. First, he urges his lover to notice the flea, which has bitten both of them and in which their “two bloods mingled be”. This would seem to be representative of sex, with the imagery suggesting the mingling of bodily fluids and the description that it “swells with one blood made of two” bringing to mind the birth of a child, that shares both its parents’ blood. In this stanza he is asking his partner to consider how insignificant these acts are in terms of the flea, and how small a thing sex is for her to be denying him. The second stanza sees Donne, or his persona, being yet more insistent. The suggestion is that sex would not only be a minor thing were she to allow it, but a significant thing if they were to deny themselves it – for the flea, he argues, is themselves and destroying it would be to destroy their relationship. In comparison to The Extasie, where Donne acknowledges the greater godliness and importance of spiritual love, we might say that he is here suggesting that physical loves is actually more important than spiritual love. In the third stanza Donne shifts the argument cleverly but illogically. First he protests that she should not kill the flea because it represents their bodily union, then when his lover has apparently killed the flea and pointed out that they are none the worse for it, he uses this to demonstrate what little loss in terms of honour their having sex would be.

The poem is composed of rhyming couplets, which are not closed, and an additional line that rhymes at the end of each stanza. The lack of full stops at the end of the couplets mean that contrasting full stops at the end of the each stanza create a sense of finality, separating the argument into three very distinct sections. The stanzas are made more distinct still by the series of three instead of two rhymes at the end of each one.