Olly Murs broke down in tears over his close friend Caroline Flack whilst live on stage.
The singer, 38, dedicated part of his performance at the O2 Arena in London to his late friend, who died in 2020.
Olly and Love Island host Caroline were pals on and off screen as they even hosted a series of X Factor together.
In honour of his late friend, Olly sung a rendition on Neil Diamond's Sweet Caroline but was seen choking up on stage.
The star revealed he had "regrets" about not being there for Caroline, who tragically took her own life aged 40.
He said: "Like I said earlier, it’s been an incredible four or five years and I know it’s been a really tough, crazy four or five years for every single one of you in this room.
"It’s going to be hard for me to do this but, in 2020, I lost a very good friend of mine, someone that I love very, very much.
"Her name is Caroline Flack and it is one of the toughest things that has happened in my life and it is really sad to see someone so amazing leave us but she has never left and she is always in my heart."
Fighting back tears, Olly added he has "so many questions that I wanted answered and I am never ever going to get them answers".
The singer and presenter urged the 20,000-strong crowd to reach out to someone they know if they're going through a tough time.
At the start of his tour last month, Olly vowed to dedicate the song to his “dear friend” Caroline at every show he ever performs.
Whilst performing at Glasgow’s SSE Arena, he said: “God, I just wish she was here. I thought I would dedicate a song to her at every show for the rest of my career.”
In an exclusive interview after the show, he said: “It’s hard to sing that in front of 12,000 people. I love Caz and it was my way of remembering her legacy, who she was in my life. I always said I don’t want anyone to forget what an amazing person she was.”
Olly also took time to hail his fiancée Amelia Tank, 30, who inspired his Marry Me album, by having her image up on screen.
He said: “I think she’s the most gorgeous girl in the world. To have her on screen was a nice moment. She was nervous about it. I said, ‘Babe, you look amazing’.
“It’s my way of bringing her on tour every day. It feels really poignant with her on it. We message every day with how many days until we see each other.”
Olly and fitness guru Amelia are believed to have set a secret wedding date – some time between gigs in Manchester on May 5 and Ireland on June 6.
If you're struggling and need to talk, the Samaritans operate a free helpline open 24/7 on 116 123. Alternatively, you can email jo@samaritans.org or visit their site to find your local branch