Who on Earth Lost?

My brother likes gambling very much.
Once he gambled with his boss,saying,"A mole is on your chest,if you don't believe it,let's bet 500 on it."
The boss said seriously,"Give me your money."Saying that,he took off his clothes,as a matter of fact,nothing was on his chest.The boss got the money happily .he told one of his colleagues that he beat my brother in gambling.
His colleague got angry, saying,"Stop it.With me,he said he could make you take off your clothes in five minutes,And the price was 1000."