The Flea is a poem written by John Donne.
The poet asks his beloved to observe the flea carefully and mark that what she denies to him is not of much significance. The flea sucked her blood, and then sucked his and in this way in its body their respective bloods are mixed up. She must acknowledge that this mingling of their bloods in the body of the flea is neither sin, nor shame, nor loss of virginity. But the flea has enjoyed her without any wooing or courtship and its body is now swelled up with the enjoying of their respective bloods, which now mingle in its body. The poet regrets that such direct enjoyment and consummation is not possible for human beings.
The beloved must not kill the flea because in its body they are more than married, for in its body her blood and his blood are mingled. Therefore, not only is the body of the flea, their wedding temple, but it is also their bridal bed. Their bloods mingle in the body of the flea as they mingle in the sex-act, despite the objections of her parents and her own objections. They have been isolated from the world and have met in privacy within the four walls which make up its body. She should not kill the poor creature, for it would be triple murder. She would kill the flea, as well as the poet whose blood it has sucked. It will also be a self-murder which is prohibited by religion. The killing of the flea would be sin and sacrilege; it would be three murders in one.
As the beloved kills the flea, the lover calls her cruel and rash. She has purpled her nails with the blood of the innocent flea. What was the fault of the poor creature, except that it had sucked a drop of her blood ? The beloved is triumphant and says that neither she nor her lover is in any way weaker for having killed it. This is perfectly true. From this she should learn that her fears of losing her honour through yielding to the advances of her lover are false. Just as she has lost little life in the death of the flea which sucked her blood, so she will lose no honour in yielding herself to him.