Story highlights Gender equity activist Dumisani Rebombo raped a girl when he was 15

He returned to see her 20 years later to ask for forgiveness

Sexual violence is common in South Africa

Dumisani Rebombo is no ordinary advocate for women's rights in South Africa. He is a rapist.

He is a rapist who sought out his victim two decades after his brutal act to ask for forgiveness.

He is all this in a nation where sexual assault has become so common that a woman in South Africa is more likely to be raped than learn to read.

Sexual assaults rarely shock anyone anymore, though a video of a brutal gang rape of a mentally disabled teenager went viral on the Internet last month. That touched a nerve.

As the young suspects face their day in court, Rebombo spoke with CNN to tell his own story -- an extraordinary tale of violence, redemption and determination to change things in his homeland.

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Rebombo was 15 when he raped.

The boys in his village of Blinkwater taunted him because he didn't herd cattle and instead went home to help his sisters. He didn't have a girlfriend.

"Sissy," the village boys jeered, and challenged him to prove his manhood.

The way to do that was by having sex. Forced sex.

Rebombo had refused until that day, when he gave in to peer pressure. He recounts what happened in a quiet, steady tone.

Two of his friends picked out a girl. They said she thought she was smarter than the boys; she didn't date anyone.

Rebombo and his friends would set her straight.

"I was afraid because I'd never had sex before," Rebombo says.

At 5 o'clock in the evening, he met his friends, drank beer, smoked marijuana.

Then it started. The first boy raped her; then the second. She was screaming. It was Rebombo's turn.

After it was over, he felt terrible, wracked with guilt and scared that his parents would find out. He says he never gave a thought about how the victim was feeling.

"It's because when the environment accepts that behavior as a norm, you don't pay to much attention to it," he says.

The South African police say there were 66,196 cases of rape in 2010-2011. But many believe that number is much higher because many rapes go unreported.

The girl Rebombo raped never reported what happened and Rebombo was never charged. She never even spoke about it with anyone. She was too scared of the consequences, Rebombo says.

"This violence, there is violence elsewhere in the world, but you don't see the staggering numbers of rapes that are seen here in South Africa," Rebombo says.

He is glad, he adds, that South Africans are finally talking about it.

Asking for forgiveness

Rebombo eventually left his village in Limpopo Province and joined first a religious organization and later an aid agency. He learned about respecting others but strangely, he says, he rarely thought about the girl he raped.

Years passed and Rebombo started working at a gender equality organization, where he spoke with rape victims about the different emotional stages they went through. That's when he thought about his victim. She did not even have an opportunity to seek counseling. Rebombo began feeling the need to make amends for his actions.

He spoke to a pastor about going to see her. The pastor told him there was no need, that he was young and boys will be boys.

Rebombo went back anyway.

He was too nervous to go to her house. She was married now. What would her husband think? How would he react?

So he arranged to meet her in the village clinic. Rapist and victim sat down together.

"I'm sorry," he told her.

Tears welled in her eyes.

Rebombo did not know what to do. He simply stood before her.

"My life has never been the same," she told him.

She told him she had been raped twice more.

Sometimes, she said, when her husband touches her, she cringes, even though she is happy with him. She suffers nightmares. She felt her life was dysfunctional because of Rebombo's actions.

He asked for forgiveness. She told him she thought he meant well. She would try to get the bitterness out of her heart.

"I felt guilt," he says. "I was embarrassed but also angry at myself that I went on with my life when she was living in misery."

'A huge monster'

A woman is raped every 26 seconds in South Africa, according to People Opposing Women Abuse, a nonprofit group for the eradication of gender violence. Rape is part of a greater environment of crime -- police reported nearly 16,000 murders last year.

The high rates of sexual violence have been explained in many ways. Some say it is a legacy of apartheid and the country's strong culture of violence.

"There's a long history of violence," women's rights activist Lisa Vetten tells CNN. "There's a long history of responding to conflict in a violent manner, of trying to solve problems through using violence.

"We also have, I think, a long history of patriarchy, of not recognizing women's rights fully, of not recognizing them necessarily as being full human beings in full -- and having all the rights of men necessarily do," Vetten says.

Some activists say apartheid is just a convenient excuse.

Jackie Branfield, a rape victim turned activist, asks how anyone can blame history for the acts of the seven youths suspected in the videotaped gang rape

"You can't blame apartheid here," she says on CNN. "You can't even blame the government. You can't blame anybody but our society for this type of violence.

"It's just that they are doing it because they can," she says, blaming what she called inefficient, understaffed and under-resourced police departments, courts and hospitals.

A Doctors Without Borders report says some have blamed an "inadequate criminal justice system, which often fails to convict, and therefore deter, perpetrators." It also mentioned alcohol and drug abuse and said lack of adequate housing and electricity make victims more vulnerable.

Rebombo, now married and settled in Mpupalanga, near the city of Durban, works for Sonke Gender Justice Network as the national manager of a "One Man Can," a project to promote healthy relationships between men and women. As such, he is out to change the national mind-set so that men will no longer think it cool to disrespect women. Violent acts must stop, he says. So must the silence of men who witness such acts.

"It's a huge monster we need to deal with," he says.

He lives every day with that monster -- and the words of his victim.

"Please teach your son not to do what you did to me."

She did not know that Rebombo has a son, who is now 28. He tells his son as well as his two daughters many things about ending gender-based violence. Respect everyone. Stick to one partner. Drink responsibly. His list is long.