He’s one of the biggest stars in Hollywood.

And on Saturday, Australian actor Hugh Jackman celebrated his 51st birthday. 

Marking his friend’s milestone anniversary, Deadpool star Ryan Reynolds serenaded the Aussie with a cheeky birthday song the next day.

Taking to his social media, Hugh wrote: ‘At first I thought – Ugh, now I have to actually apologize. But then,’ alongside a clip of Ryan. 

‘Hello Hugh, I was just going to wish you a happy birthday… and then I saw what you said, and in a word… hurtful, enjoy the show.. Hugh Jackman’ Ryan said in the video. 

He then began to start singing Happy Birthday.

Birthday tribute: The 42-year-old Canadian took to his own Instagram account to wish Hugh a cheeky birthday message, putting a cake sticker over the Wolverine’s star’s face 

He concluded the clip saying: ‘And I’m not f**king professionally trained you Jackman you piece of sh*t.’

The 42-year-old Canadian took to his own Instagram account to wish Hugh a cheeky birthday message, putting a cake sticker over the Wolverine’s star’s face. 

Hugh hit back re-posting the birthday snap with an animation of Judge Judy Sheindlin rolling her eyes on top of Ryan’s face. 

Hit back! Hugh re-posted the birthday snap with an animated gif of Judge Judy Sheindlin rolling her eyes on top of Ryan’s face

Earlier in the day, the Greatest Showman star shared a photo of him holding a cupcake, and thanked fans for the sweet birthday messages. 

‘Thank you for ALL the awesome birthday messages,’ he captioned the snap.

Meanwhile, The X-Men favourite has had an on-going comedic ‘feud’ with fellow superhero actor. 

‘Thank you for ALL the awesome birthday messages’: Earlier in the day, Hugh Jackman (pictured) star shared a photo of him holding a cupcake, and thanked fans for their messages

Back in September, Pokémon Detective Pikachu star ruined took the opportunity to offer a gushing congratulations to Hugh after the Wolverine star was awarded with the Order of Australia in Canberra.

Re-posting a photo of Hugh after his win, Ryan joked: ‘Hugh is one of the finest, kindest, hardest working, generous and most talented people…None of this changes the unfortunate fact he’s a complete bastard.’  

Hugh and Ryan have been comedic adversaries for a few years, with Ryan often gently taking the mickey out of Hugh on Twitter, and vice-versa. 

Hugh recently ribbed Ryan him by inviting him to a party and falsely telling him it was a sweater bash.

‘These f***ing a******* said it was a sweater party,’ Ryan wrote on social media in a shot alongside his rival as well as fellow A-lister, Jake Gyllenhaal, 38.  

What feud?  Hugh (left) recently ribbed Ryan (center) him by inviting him to a party and falsely telling him it was a sweater bash. ‘These f***ing a******* said it was a sweater party,’ he wrote on social media in a shot alongside his rival as well as fellow A-lister, Jake Gyllenhaal (right)