1) You lose the bet
I.e. You give him $2, he gives you $3 (you earned $1) but have to return him the $1 because you lost the bet. So nobody gets more money.
2) You win the bet
I.e. You give him $2, he doesn't gives you no money, so you win, and you get $1 back from him, you lose $1 in the end.