To Flea or Not to Flea?

After reading and rereading about 20 times, I still don't have the most clear idea of what Donne is portraying in this poem. But this is what I have concluded from the work. In the first stanza, the narrator speaks of a flea for the purpose of its insignificance. In the second line, he compares how little the woman he is speaking to denies him. They both "sucked" out this denial, and now, because the denial is small, it is not a big deal that their "two bloods mingle" aka have sex. It cannot be said a shameful deed, and in the phrase "more than we would do" the narrator is implying that the sex will amount to more.

In the second stanza, the flea now holds them together, containing their lives and its own. The third and fourth lines read "this flea is you and I and this, our marriage bed" emphasizing this bond. Though they have a "parent's grudge" on their minds, they are hidden together in "living walls of jet." This metaphor of dark living walls could symbolize a vagina. And the phrase that follows- "though use make you apt to kill me," makes sense in this light because although she could be angry after having sex, he urges her not to, as it would kill him, her and the flea.

In the final stanza, the woman is "cruel and sudden" as she "purpled [his] nail in blood of innocence." Although he thinks their sex is innocent, she has chosen to leave him purple and without it. The flea is gone, dead and so is he. He claims that she has "triumphed" and has "so much honor" when she "yielded" to him.