Virulent

Scientists say that the Slow loris is the only venomous primate

And yet I have loved some of the most toxic and malignant people

Who secrete deceit and prattle poison

The kind of venom that will numb you into a sense of security

A bane that eats you from the inside out

Not breaking your heart, but rotting it

Obnoxiously noxious

A truly pestilential partner

I think scientists need to run some more tests