Bear Grylls shares rare picture with his son and everyone is saying the same thing

Bear Grylls might be a survival expert, adventurer, former SAS trooper and TV star, but he's also a father too.

For some reason, a lot of us seem to forget that the 49-year-old has a life, family and hobbies after watching one of his shows where he navigates life in the wilderness for a few weeks.

There's nothing like seeing Grylls drinking his own p*ss or eating a sheep's eyeball to make you overlook every other aspect of his life, eh?

In between filming daring new series, which document his antics in the great outdoors, the world renowned survivalist is playing dad to his three kids Jesse, 20, Marmaduke, 18, and Huckleberry, 15.

The Northern Ireland-born star shares his three boys with his wife of 24 years, Shara Cannings Knight, who he met on New Year's Eve in 1998 while naked from the waist down.

Don't worry, he wasn't being indecent - Grylls hilariously lost his pants after they were dragged off when he was hit by a wave on the north coast.

Recalling their first meeting on Piers Morgan's Life Stories, he said: "I was running around naked, trying to find my trousers. It was the worst timing in the world to fall in love because I was up in Scotland."

The Bear's Wild Weekend star even reenacted their bizarre first encounter when popping the question to Knight, revealing that he 'pulled out the ring from his butt cheeks' after skinny-dipping.

Bear Grylls shared a birthday post dedicated to his 18-year-old son. (Instagram/beargrylls)

And as they say, the rest is history - the pair got hitched in 2000 before going on to welcome three boys into the world.

Or should I say cubs, seen as though their dad is the Bear Grylls?

His sons stay firmly out of the spotlight for the most part, instead crafting their own way in the world - but obviously, they've inherited a string of qualities from the adventurer.

Grylls' eldest kid, Jesse, for example is just as much of a thrill seeker as his father and also attempts daredevil stunts.

Each of the Eton-educated brothers resemble their parents too, however, they all seem to far exceed Grylls and Knight in the height department.

Social media users were left stunned when the dad-of-three shared a rare picture with his lookalike son Marmaduke to commemorate his 18th birthday on 6 April.

The celeb wrote: "18 today! We love you so much Marmaduke… keep shining bright!"

People couldn't believe how tall Marmaduke was compared to his parents. (Instagram/beargrylls)

As well as being shocked that his boys were now all grown up, people couldn't stop talking about the size of Marmaduke - while simultaneously rushing to Google how tall Grylls was compared to his son.

One said: "What have you been feeding him! 18 and already looks incredibly strong."

Another laughed: "Bear Junior is turning out to be a Grizzly."

A third joked: "I think drinking p*ss somehow created a super human?"

A fourth added: "Bear Grylls looks like he is the son."

While a fifth commented: "I think your son is the real bear here. Damn, so tall."

Others asked if the 18-year-old was 'standing on something' as he completely towered over his mum and dad in the snaps.

In a post celebrating Marmaduke's 17th birthday last year, Grylls described his son as a 'kind, fun, gentle, loyal, young man' who was also '6ft4 strong'.

Seen as though his growth spurt has probably continued over the last 12 months, it's clear that the youngster is going to dwarf his dad from now on.