My life was made hell for months by an ex who threatened self-harm/suicide after I broke up with him. Have some sympathy for the girlfriend as well - she knows a guy who considers stabbing a legitimate form of negotiation is obsessed with her. Self-harm under these circs CAN sometimes be used deliberately as, or experienced as, a threat. "I'll hurt myself if you leave me" is not a million miles away from "I'll hurt you if you leave me" - the cases of guys who've killed their kids then themselves when a relationship breaks down illustrate that.