Jonah Hill couldn't resist making a joke about how many celebrities his friend Adam Levine at his wedding to Behati Prinsloo.

Jonah Hill

Jonah Hill

The 32-year-old comedian officiated proceedings when the Maroon 5 frontman tied the knot with the Victoria's Secret Angel on July 19, 2014, in Cabo San Lucas, Mexico, and was chosen for the role by Adam because they have been friends since junior high school.

Jonah recalls scanning the room at the reception and noticing a lot of very famous faces and couldn't resist making a gag about Adam's choice of guests.

During an appearance on 'The Howard Stern Show' on Sirius XM Radio, he revealed: "The joke I wrote was like, 'Adam and I grew up together ... it's so nice to see all the people we grew up skateboarding with ... like Stevie Nicks and Robert Downey Jr...'"

Jonah remembers he was very nervous about doing a good job on the day and once his responsibilities were over he felt very "drained".

He said: "I left the party after like 30 minutes."

Despite his concerns, the 'War Dogs' star was honoured to be asked by Adam, 37, to do the job because he considers the 'Animals' singer to be his "brother" and their dads were friends from school themselves.

He explained: "Adam Levine is genuinely like family to me. We're literally like brothers."

As a teenager, Jonah went on to study Crossroads School in Santa Monica, California, and was a student there at the same time as former 'Hills' star Stephanie Pratt.

The pair have remained friends and last week she attended a screening of his new movie 'War Dogs' in London and praised him for being hilarious at school.

She told BANG Showbiz: "We went to the same private school ... He was just a joker, a clown. Super self-deprecating and he was friends with everyone."

The pair are not the only Crossroads High School alumni to go on to become famous.

Other star students include Stephanie's brother Spencer Pratt, Kate Hudson, Liv Tyler, Zooey Deschanel, Michael Bay and Gwyneth Paltrow.