Liar Liar Their Pants Are On Fire: Sunday’s Comic

While it's accepted that politions lye these two are on steroids

From the Urban Dictionary:

Liar Liar Pants On Fire

Liar Liar Pants On Fire is a phrase that children like to scream at each other whenever they think the other is lying. They also like to scream it at adults who tell them stories about fairies. It is an overall stupid thing to say, since if your pants actually caught on fire when you lied, more politicians would be dead.