...I just remembered a sweet little lady at the front desk from an old internship I had many, many years ago. She was telling me about her abusive ex-husband, and how when she finally worked up the courage to leave, he started trying to lay a guilt trip on her about how he would kill himself if she left.
She mentioned how she went to a friend of hers for advice about what answer to give, and it worked beautifully.
The next time he started in on how he can't live without her and he'd commit suicide if she left, she announced, "That's okay, I look good in black." Shortly thereafter, he found a girlfriend, and never bothered his (now-ex-)wife her again.
Seems a little heartless, but threats like these are another form of manipulation, and allowing any kind of manipulative influence is detrimental to our health.
(For the record, I'm not sure I'd have the guts to say that. I get too wrapped up sometimes, and always wonder about that "What if he means it?")