When the sexual enjoyment derived from one's own pain/humiliation clashes with their want to end their own life. It usually forms into wanting someone to
hurt them to the
point of fatality, masking it in a sexual
light.
Her: "I want you to choke me."
Him: "Okay."
Her, later: "Oh my god, please step on me."
Him: "Okay...?"
Her, even later: "Step on me and
just crush my spine, dude!"
Him: "I'
m mildly uncomfortable now. You'
re bordering on suicidal masochism."