Vex stared at Jack for a moment, finding himself speechless for the first time in quite a long time. Jack was going to kill himself. Jack had come over to his apartment to kill himself. "You know, mate, Storybrooke isn't that bad of a place. You don't have to kill yourself just because you've found yourself stuck in the middle of nowhere. Have a drink instead." Because drinking was a healthy option. Well, it was healthier than killing oneself.
He decided this was definitely a good time to have another shot. So he poured himself one, and downed that one. Three shots in the matter of minutes. That was okay, right? Especially when one's house guest just informed you that he was going to stab himself to death.
"So, tell me why I should allow this to happen." Vex, being a mesmer, did have the capability of stopping Jack from doing this. As long as Jack didn't have some sort of strange power that made him resistent to Vex's mesmer abilities.