Justin Bieber has been endlessly mocked both on- and off-cam over his recently released Calvin Klein underwear ads. There's been numerous photoshopped images, memes and even an "SNL" spoof.

However, the 20-year-old pop star has the approval of an underwear modelling expert: retired football superstar David Beckham!

The 39-year-old athlete recently revealed to E! News that he's impressed with Bieber's ads. "Not bad, not bad, not bad," he said. "He looks good in his underwear ads. He looks very good."

Whether or not Bieber's critics agree, Beckham definitely knows what he's talking about. He's stripped down to his underwear in adverts for industry giants like H&M and Emporio Armani.

When told by E! interviewer Marc Malkin that he looked good as well, Victoria Beckham's husband laughed as he replied: "Thank you, but I'm slightly older."

He's older, definitely, but fans of the football hero would agree that he's no less hotter.

One person who was definitely not a fan of Bieber's new sexy photo shoot was Rhea Durham, wife of Mark Wahlberg who made a big splash with his Calvin Klein underwear campaign back in 1992. She threw a bit of shade at the pop star by hinting that most of Bieber's toned body was the result of Photoshop.

"My baby was the 1st and the best and not to mention…..wow the retouching," the 36-year-old tweeted shortly after the new ads were unveiled, taking a jab at Bieber.

She wasn't the first one to poke holes at Bieber's CK advert either.

"Saturday Night Live" regular Kate McKinnon channelled the Canadian crooner in a spoof ad, mocking Bieber's age, tattoos and even his "big wiener."

"Are my muscles cute?" she says at one point in the clip, before smelling her armpit and gagging at the stench.

The spoof ad also referenced to accusations claiming Bieber had his bulge edited to look bigger, with lines such as "My Calvins, clothes for my big weiner" and "Yeah my pee pee's in there," in which McKinnon proudly points to her overly-padded crotch region.

And while he may have been the butt of many jokes, Bieber proved that he has a sense humor when he took it all in stride.

"Well played. Lol," he posted on his Twitter to show his appreciation one day after the clip was released online.

Meanwhile, check out Bieber's, Beckham's and Wahlberg's underwear ads below and find out who's the hottest!

Justin Bieber for Calvin Klein

David Beckham for H&M and Emporio Armani

Mark Wahlberg for Calvin Klein