STORY: This video went viral and provoked an outcry in Spain.
A male student in Madrid yells obscenities at women at the nearby all-female dorm, calling them "whores" and "nymphomaniacs".
Fellow students at the men's dorm switch on their lights, open shutters and howl in unison.
The student also threatened to make the women submit at a "capea" - an outdoor party and amateur bullfight usually involving heavy drinking.
On Friday (October 7), Spanish prosecutors launched a criminal hate-crime investigation into what Prime Minister Pedro Sanchez called "inexplicable, unjustified and absolutely repugnant behavior".
The university also said it was probing the incident, which took place last Sunday (October 2). The dorm says it has expelled several of the perpetrators.
But in an open letter posted online, some residents of the Santa Monica female dorm accepted their male neighbors' apologies, calling the insults a "traditional practice" at student residencies.
And fuelling debate in Spain over what some say is deep-rooted machismo in the culture.
This resident, who didn't give her name, was among many to shrug off the incident.
“It is being hyped-up and taken out of context. Yes, we have a good relationship with them. We don't feel offended at all.”
Male students at the dorm also said it happened every year. Juan Melo says he still felt ashamed.
“Like the rest of my colleagues - the ones who took part and the rest of them, like me, who didn't - we are ashamed and sad because those insults are intolerable and above all because of the image it gives the residency and our relationship with Santa Monica, which doesn't reflect reality.”
Spain's largest student union has announced a protest for Monday (October 10) and demanded the expulsion of everyone involved in the, quote, "disgusting and sexist" footage.