The fracas erupted between gypsy clans in eastern Spain when a member of one family let rip while walking past a young man from the rival family shortly before midnight on Sunday, local newspaper Diario Informacion reported.
The young man returned the insult in the same way; by farting in his direction.
The situation quickly escalated with a wife of one the men joining the fray claiming she was insulted, and then the other man's wife also getting involved, until guns were pulled and shots fired.
"In that way, what began as a bit of silliness grew more and more violent and ended up with a double shooting," reported the newspaper.
A 57-year-old was shot three times in the stomach and is being treated in the intensive care unit at Valencia Hospital where his condition is described as "serious".
His 29-year-old son received a bullet to the leg but is expected to make a full recovery.
Two other men were taken to hospital, but have since been discharged and four people have been arrested.
Around 50 police officers have been sent to patrol the neighbourhood of Xenillet in Torrent to keep the peace amid fears of revenge attacks. Other teams have been posted outside the hospital.
The neighbourhood is home to a large number of gitano families and the two clans involved in the scrap have been sworn enemies for decades, local media reported.
Note: The Local has chosen to use the term gypsy (a translation of the Spanish word 'gitano') because the word itself doesn't have negative connotations for people within that community in Spain.