That isn't playing dirty, that's outright emotional abuse, demanding someone else take responsibility for her not committing suicide. Al is appalled, but at least being appalled is keeping him from sinking back down into his own depression.

"You can't say something like that, Steph. You can't put the responsibility of your life on my shoulders completely, you have to fight for yourself. I can protect you, and I can help you, but I can't fight for you."