The president of the Saint Mary's Students Association says allowing a chant about sexual assault to be performed at a frosh event is the “biggest mistake” he’s ever made.

A video of students chanting about the sexual assault of underage girls surfaced online this week, sparking outrage on campus and on social media.

The chant was performed by 80 frosh leaders – both male and female – in front of about 300 of their first-year peers at a frosh week event held Monday.

The students are heard chanting “SMU boys, we like them young. Y is for your sister. O is for oh-so-tight. U is for underage. N is for no consent. G is for grab that ass.”

The video has since been removed from Instagram, a popular social media sharing site.

Jared Perry apologized for the incident during a news conference Thursday afternoon and admitted to reporters that he too had joined in the song.

“It’s a mistake. It’s definitely the biggest mistake I’ve made throughout my university career and probably my life,” he said, as about 20 of the student leaders stood silently behind him.

Perry said they will be investigating the incident in order to determine how the school can prevent sexual assault on campus, while addressing what he referred to as a "culture of sexism" at the university.

“Saint Mary’s University Students Association entirely condemns these chants,” he said. “This event highlights that sexism exists on SMU campus just as it does, I would hazard to say, on most, if not all, campuses across this country.”

He added that the same chant has been part of frosh events since at least 2009 when he was a frosh, with the lyrics being passed down on paper to orientation leaders.

However, he couldn't explain why no one had raised concerns about it previously.

"The fact that this sort of thing was able to happen at this scale and that some (leaders) don't understand the seriousness of it tells me that there is a problem of a culture of sexism that demands attention and real action on this campus," he said.

Perry has since stepped down as the chair of Students Nova Scotia, but will stay on as president of the Saint Mary's Students Association.

“Look forward, we want to be some serious advocates about sexual assault and we want to turn this around and educate more students on it.”

SMU president ‘shocked’ by sexual assault chant

The president of Saint Mary’s University has also apologized for the incident, saying he is “embarrassed” and “ashamed.”

“As a parent and a grandparent of a young baby daughter, yes I am. I’m sickened,” says Colin Dodds. “I’m very, very dismayed, but we have to move forward.”

Dodds says he and his colleagues were “shocked” by the video and says the students’ behaviour doesn’t represent the values of his school.

He says the chant contains offensive lyrics, is completely inexcusable, and violates the university’s commitment to upholding the values of equality and respect.

“The university regrets that this was allowed to occur and we apologize unreservedly,” says Dodds. “I am taking measures to ensure it does not happen in the future.”

He says frosh leaders met with school officials and a police officer before the event to talk about sexual assault and sexual consent.

“However, I accept that I and the university administration have a role to oversee and guide student leaders. We failed in that responsibility,” says Dodds.

Dodds says he has called for a special meeting with the executive and board of the student association, asking them to explain what happened.

He says the 80 student leaders involved in the incident have been mandated to take a sensitivity seminar conducted by specialists and university staff by the end of the month.

Premier Darrell Dexter ‘disturbed’ by video

Nova Scotia Premier Darrell Dexter has also weighed in, saying he was disturbedafter watching the video.

"I think, like everyone else, it's disturbing," Dexter said Thursday.

"You know, kids, they often act without considering, necessarily, the consequences of the things that they're saying. It was very disturbing."

Dexter said he thinks the students would have acted differently if they had thought about what they were doing.

"I also felt bad for them as well, because I think if they had sat for a second and thought about it, they wouldn't have engaged in that kind of behaviour, particularly in this province, it's is a very, very sensitive thing."

The province recently launched an ad campaign aimed at young men to educate them about consensual sex.

The government has been focusing on raising awareness around consensual sex and bullying following the death of Rehtaeh Parsons earlier this year.

The 17-year-old attempted suicide after she was allegedly sexually assaulted by several young men at a party in 2011.

“My hope, and I think this is probably the hope of the student leaders and of the administration, is that this will be resolved among the kids, that it won’t happen again and that these guys can get on with enjoying their frosh week and onto what they’re really there for, which is a decent university education,” says Dexter.

With files from CTV Atlantic's Kelland Sundahl, Nick Ritcey, Sarah Plowman and The Canadian Press