Someone says, "Everything I say is a Lie."

Someone says, "thats where your head explodes..."

You say, "I say that you're liying about this. but that doesn't imply that you always tell the truth. Just that you don't always lie."

Someone says, "Hmmm interesting."

You say, "That's how you answer that."

Someone says, "I see..."

You say, "The implication is that if that statement's true, it's false because you always lie. But if it's false, you always tell the truth,
which isn't implied by the statement. The only thing that the statement can prove or disprove is wether you always lie."

You say, "Since you can't always lie, for then the statement would be the truth, but it can't because you always lie, so you don't always
lie, but you don't always tell the truth. Thus, you sometimes lie, and sometimes tell the truth, and you're lying this time."

You say, "QED."

Someone says, "Wow..."