Mark Wahlberg was taken aback when Justin Bieber sent him pictures of him in his underwear.

The 45-year-old actor - who stripped down to his tighty whities in a photoshoot with Calvin Klein in 1992 - has admitted the 22-year-old singer bombarded him with half naked images of him from the My Calvins Spring/Summer 2016 campaign, which Mark has hinted made him feel very uncomfortable because he is a man over twice his age and has children.

Speaking about the moment the 'Sorry' hitmaker's raunchy portrait flashed up in his inbox, the 'Deepwater Horizon' star - who has sons Michael, 10, Brendan, eight, as well as daughters Ella, 13, and seven-year-old Grace with his wife Rhea - said: ''He did send me the pictures and I was like, 'You don't send a guy pictures like this in your underwear.'

''He was proud, you know, it was a big deal for him to do. And I was like, I am at 45, a dad and a husband, a father of four, I'm trying to move away from that image.''

Although Mark has described the Canadian-born star as having ''attitude'', he has admitted he was ''the biggest punk in the world'' when he was younger and would have made Justin look like an angel if the pair were to be compared to one another at the same age.

He explained: ''You know what? People give him flack for growing up in the spotlight and they say he has a bit of an attitude, but look at the look on my face, I mean, I was the biggest punk in the world. He's very nice and young and polite in comparison to what I was.

''Actually, you know what, he is a very nice young man, he's a friend of mine, I've spent time with him.''

And the dark-haired hunk says that despite looking proud of himself in his commercial for the longstanding American brand as he grabbed at his crotch, he has admitted it wasn't his ''proudest moment'' of his career.

Speaking on the American talk show 'Conan', he said: ''Well, I can't say I [haven't] done worse things, but that wasn't one of my proudest moments.''