During a candid new interview, Bono unveiled a deep personal secret about his family, that led to regrets over his teenage behaviour, and commented on his mocked poem about Ukraine.

After more than four decades in the public eye, the U2 frontman revealed he has a half-brother, whom he has never spoken publicly about before. Bono explained that he was born after his father, Brendan “Bob” Hewson, had an affair while living in their Dublin home along with his brother Norman and their mother.

READ MORE: U2’s Bono & The Edge Perform Surprise Show In Ukraine Bomb Shelter

Speaking with BBC Radio 4’s Desert Island Discs Sunday morning about his forthcoming memoir, Surrender: 40 Songs, One Story, the rockstar shared how he found forgiveness and peace, resolving his strained relationship with his late father, who died in 2001.

“I do have another who I love and adore,” Bono, 62, told the radio show, referring to finding a sibling “that I didn’t know I didn’t have … or maybe I did”.

Learning of his half-brother’s existence and a secret romance helped the singer rationalize his father’s behaviour at the time of his mother Iris’s sudden passing, when Bono was 14-years-old.

READ MORE: Bono Cheers Papal Program For ‘Inclusivity,’ Educating Girls

“My father was going through a lot. His head was elsewhere because his heart was elsewhere,” Bono recalled. “I could tell my father had a deep friendship with this gorgeous woman who was part of the family and then they had a child which was all kept a secret. Nobody knew.”

After discovering the truth, Bono questioned his father about their family life.

“I asked him, ‘did he love my mother?’ He said, ‘Yes.’ And so I asked him ‘how could this happen?’ and he said, ‘it can,’ and that he was trying to put it right, trying to do the right thing. He wasn’t apologizing, he was just stating these are the facts. I am at peace with it.”

The truth left Bono feeling regretful about his teenage years. “I am sure I was hard to deal with. He was coping with other stuff in his life. He was very droll and very funny. But it got rough,” he admitted. “I feel like I wasn’t there for him,” he said before recalling a formal apology he made to his deceased father at a chapel in France.

READ MORE: Bono Turns Off The Radio When A U2 Song Comes On Because His Voice Makes Him ‘Cringe’

“There was nobody there, I lit a candle and I got on my knees and I just said, ‘look I’m sorry I wasn’t there for you, you went through a lot and please forgive me’ and I felt free.”

Bono went on to explain that his mocked poem addressed to the people of Ukraine, which was read on St. Patrick’s Day by Nancy Pelosi, was taken out of context.

“I write limericks sometimes for the Paddy’s Day event. It took 10 minutes, it was trying to be a satire, funny and the speaker of the house, who is an incredible woman, instead of saying ‘limerick’, said it was a poem and so people thought it was like Seamus Heaney,” Bono said.

“I deserve a slap,” he added. “Every singer in a rock and roll band is going to say the wrong thing. But that poem business is ridiculous. It was just a limerick.”