Mexican fans of the Oakland Raiders chanted the gay slur ¡Puto! during the game between the Raiders and Houston Texans in Mexico City Monday night. The slur could be heard on the ESPN broadcast, growing louder as more of the stadium got in on the act as the game progressed.

The game was technically a Raiders home game and the crowd was heavily supporting Oakland. The chant had been heard at least a dozen times during the game on kicks: When the Texans tried a field goal; kicked off following a field goal and touchdown; attempted an extra point and on two punts. In addition to what was heard on ESPN, fans at the game were reporting hearing the slur.

The slur is a a regular occurrence at Mexican international soccer matches has gotten so bad that the national team asked fans not to chant it. FIFA, soccer’s governing body, has fined the team for the chant but nothing has stopped it. ¡Puto! is chanted when the opposing goalie does a free kick.

This was the first NFL regular season game in Mexico since 2005 and hearing this ugly slur was disgusting.

A source close to the NFL has told Outsports that the league was aware of the issue before the game and reached out to Azteca Stadium management to see what could be done. As we know from Mexico soccer matches, no one has figured out how to stop the chants — in-game announcements exacerbate the problem.

A spokesperson for ESPN had no comment.

In 2014 during the World Cup, I asked Andres Aradillas-Lopez, an economics professor at Penn State who was born and raised in Mexico, to explain why puto is a slur, since many deny it. Aradillas-Lopez is not gay. Here was his reply:

"Another international soccer tournament, another opportunity for Mexican soccer fans to showcase their ugly 'puto' chant to the world. Concomitant with this come the apologists who claim that this chant has nothing to do with homophobia. Their argument is that 'puto' in a wide sense simply refers to someone who suffers from a 'lack of manhood' but not necessarily gay.

"What they omit to say is that 'puto' has always been a derogatory term used against gay men and, therefore, is a gay slur. In the macho universe, gay men are a subset of the universe of 'putos' (I would like them to tell me why, then, do they not chant 'puta' at women's soccer games).

"This defense of the 'puto' chant is as weak as the defense of the Confederate flag as a symbol of heritage and not of racism: 'This flag honors my ancestors' or 'This flag was used in the Dukes of Hazard, a lighthearted, fun TV show.' As clear as it is that the Confederate flag is a symbol of racism, the word 'puto' stands for a gay slur and the reason, in both cases, is very simple: The person waving that flag or chanting that word does not get to decide the meaning of those symbols. It is the groups who have been VICTIMIZED by those symbols who get to decide.

"And this is not up for debate, not even by the most ardent puto-apologists: almost every gay man in Mexico at one point in their lives has been called 'puto' in an offensive, threatening, derogatory way. This is what makes it a homophobic chant, which is inexplicable in a country that legalized gay marriage even before the United States. It is too sad that this embarrassing chant has become Mexico's most notorious contribution to the world of sports as of late.

"Mexico is not a homophobic country; for some reason soccer fans acquire a mob mentality and start chanting this word like automatons. One-on-one, 99.9% of them would never say it. Nevertheless it HAS to stop."