"The Flea"

This poem is kind of weird and confusing, but all poems seem to be that way. What I get from the poem is that a flea drank the blood of both lovers.  The man is frustrated that the two cannot be together because their parents don't approve.  The girl wants to kill the flea because its just a nasty insect but the boy likes that their blood is together, like marriage.  The girl kills the flea and the boy feels betrayed.