You shouldn't punch someone in the stomach.
Tony is at the bar when someone bumps into him causing him to spill a drink.
Tony wants to confront the person, and not be seen as a coward.
"Tony turns and faces the individual, and says, ""Hey, you caused me to spill my drink""."
Tony immediately turns to the person, punching them in the stomach.
The person offers to buy Tony a new drink, and they end becoming friends who laugh about how they met.
The bar's bouncer grabs Tony by the shoulders and throws him out of the bar, causing Tony to bruise some ribs and be in pain for a few weeks.