Arnold Schwarzenegger's son Patrick shares fun snaps and very cheeky message as he marks Terminator star's 77th birthday

Arnold Schwarzenegger turned 77 on Tuesday with his eldest son Patrick sharing a very cheeky message to his father.

The Terminator star, who is in a long-term romance with Heather Milligan, 49, was lauded by Patrick, 30, who shared a cute throwback snap of the pair to Instagram.

In the snap - captioned 'Happy birthday pops' Patrick - who looked to be around seven years old - posed with his father in a gold photo frame.

He also shared a fun snap of the actor posing in a shirt with his image emblazoned on it with the hilarious caption:  'I love you almost as much as you love yourself!'

Arnold shares Patrick, Katherine, 34, Christina, 31, and Christopher, 26 with ex-wife Maria Shriver.

Arnold Schwarzenegger turned 77 on Tuesday with his eldest son Patrick sharing a very cheeky message to his father

Arnold Schwarzenegger turned 77 on Tuesday with his eldest son Patrick sharing a very cheeky message to his father

He is also father to son Joseph Baena, 26 from his affair with former housekeeper Mildred Baena. 

Last month Arnold paid tribute to his former rival Sylvester Stallone as he marked his 78th birthday.

The Rocky star - who recently wished his 'amazing daughter' Sistine a happy 26th birthday late last month - was called a 'champion' by The Terminator actor, 76, in a post uploaded to his main Instagram page. 

Alongside three images of the pair taken throughout the years, Arnold typed out, 'Happy birthday my friend @officialslystallone.' 

'You are a champion and a legend. You inspire me and billions of people around the world,' he concluded.  

One picture showed the two standing next to each other as they prepared to carve pumpkins that were placed in front of them.

A second snap was taken of the two stars years earlier as they both donned Planet Hollywood T-shirts. 

He also included an additional throwback photo as they posed for a picture while standing outdoors, with others joining in.  

He also shared a fun snap of the actor posing in a shirt with his image emblazoned on it with the hilarious caption: 'I love you almost as much as you love yourself!'

He also shared a fun snap of the actor posing in a shirt with his image emblazoned on it with the hilarious caption: 'I love you almost as much as you love yourself!'

Arnold shares Patrick, Katherine, 34, Christina, 31, and Christopher, 26 with ex-wife Maria Shriver

Arnold shares Patrick, Katherine, 34, Christina, 31, and Christopher, 26 with ex-wife Maria Shriver 

He is also father to son Joseph Baena, 26 from his affair with former housekeeper Mildred Baena

He is also father to son Joseph Baena, 26 from his affair with former housekeeper Mildred Baena 

Arnold and Sylvester were involved in a years-long rivalry - which has since fused - and seemingly began in 1977 when they were seated at the same table at the 34th Golden Globe Awards. 

Stallone claimed that Schwarzenegger had laughed when Rocky lost in a few categories during the ceremony, but when the film won Best Motion Picture - Drama, he threw a bouquet of flowers at the star. 

Arnold later revealed that he was, 'the one who started this whole thing...by opening up my mouth, saying stupid things, being competitive.'

However, decades later, the pair have a close friendship, with Arnold saying he admires Stallone's 'dedication and his passion.' The Rocky star also said the Predator actor has a 'big heart.' 

But earlier this year in April, the two took part in a joint interview to reflect on the rivalry that has since ended for TMZ Presents: Arnold & Sly: Rivals, Friends, Icons, per People.  

Last month Arnold paid tribute to his former rival Sylvester Stallone as he marked his 78th birthday

Last month Arnold paid tribute to his former rival Sylvester Stallone as he marked his 78th birthday 

At one point, Arnold credited his success in the industry to Sylvester and explained, 'There's no two ways about that: He was very helpful in my career because I had something that I could chase.'

Stallone added that when Schwarzenegger, 'came along I was like finally, something to motivate me. Because he is, dare I say it, competition, a threat, whatever word you wanna use.' 

'As soon as I saw him it was like bang, two alphas. If we walked into a party we'd be staring at each other for a few seconds and then "I gotta get that guy. He didn't do anything wrong but he will."'