The Flea appears deceptively casual in its composition and style but is infact a complex argument. Sentences such as "And this, alas, is more than wee would doe" epitomise the misleading colloquial language. When commencing the first stanza there are insinuations of a conversation continuing, although the reader is only allowed a one-sided version. Donne personifies his argument into a flea, and demonstrates how little he request from her after the flea has bitten her (although there have been alternative suggestions of a pun on "flea" and "flee", in reference to the fleeting nature of love). He emphasizes that the mingling of their blood within the flea was presently occurring, explained through vivid imagery, such as "and cloystered in these living walls of Jet". Nature actively combines, mingles, and unifies, whatever things we take for granted as physically separate and individual. Nature doesn't just have a sort of intrinsic unity it actively combines and connects. However this flea had not waited for marriage and it was neither regarded as a sin nor a loss of virginity. In Donne's day it was thought that sexual intercourse literally involved the combination of bodies, making one of two. The union of their blood is satisfactory for him, as it doesn't require him to woo her. This imagery of the flea and its violation of the female draw Donne to wonder why humans are not more like insects.
But this intelligible argument fails to convince the lady who presently crushes the flea, killing it, with the speaker begging for her to "three lives in one flea spare" its life. He asks of this due to the union of their blood representing that they were "almost" married, which was swiftly altered to "more than" married. This concept of marriage transforms the flea into a temple, a place where one can be sacramentally united; the flea is the actual "bed" where they were physically united. He considered their coming together as a triumph over the obstacles of the parent's opposition and the lady's refusal to commit to him.