Ryan Reynolds and Rob McElhenney went to "monarchy boot camp" before meeting King Charles .

The pair - who are co-owners of UK football club Wrexham A.F.C. - were asked to meet with the new monarch and his wife Queen Camilla at the team's ground in Wales in December and Ryan has now revealed they hired an etiquette coach to whip them into shape ahead of the big day.

Speaking in a trailer for the new season of their documentary series 'Welcome To Wrexham', Ryan explained: "So the King of England called ... We went to monarchy boot camp. It was like the military except your pinky is always up."

The teaser showed them meeting with the coach who was instructing them how to give a proper handshake, telling them: "Everything begins with the first impression. Let me see the two pumps and release."

Another moment shows Ryan sitting very still in a chair with the actor joking: "I feel like a serial killer."

The clip was shared on the show's official social media pages with the caption explaining the co-owners got a "crash course in royal etiquette" and the meeting with the royal couple was filmed for the second series.

Speaking after the meeting, King Charles admitted he was thrilled to see sport in the town of Wrexham doing so well. He said: "I had the opportunity to see one of the other wonders of Wrexham, namely the football club, which is busy putting Wrexham on the map as never before."

Ryan also posted a picture of the meeting on his Instagram page, and joked: "'Welcome to Wrexham Season 2: Charles in Charge'."

In an interview with The Athletic last year, Ryan admitted he's enjoyed the ups and downs of owning a football club, but he's determined to to be "respectful" to all the fans.

He explained: "I would say that going into anything like this, where you’re in sort of uncharted territory - at least for us - it’s just about transparency. We’re not here to project some idea that we know what we’re doing in terms of running a football club.

"We are here to say that we’re gonna be responsible, respectful and reverent of the institution that is Wrexham and that we’re going to do everything we can to grow this and build this like we would any other business, or film or television show or anything like that ...

We just went in very honestly and said look, your average five-year-old in Wrexham has forgotten more about football than we will ever know. But we are going to do our best to make sure that the success of the club is commensurate to the success of the community, and vice versa."