Don't what? Go to war among themselves? They don't 'ave much of a choice if yours truly offs it. All three are too proud to let one of the others gain the prize, and they each 'ave a reputation to keep up in Hell and surrendering a deal would be 'umiliating.

So, as much as they might hate the idea, they don't 'ave too much of a choice but to keep me alive.

[Which didn't stop the First of the Fallen from giving him his lung cancer back briefly just to be an arsehole.]