Friends guest star apologised to cast after admitting to being 'd**k' on set

The actor behind one of Friends' most 'hated' characters was forced to issue an apology to cast and crew following his appearance on the show, admitting he behaved as poorly behind the scenes as he did in front of the cameras.

And I bet we can give you a clue as to who by telling you we 'hate that guy!'...

The much-loved 90s sitcom introduced viewers to its fair share of controversial characters back in the day.

Some we loved to hate - like, Janice (Maggie Wheeler) and her nasal-y voice, Will (Brad Pitt) and his 'I hate Rachel' club, and Phoebe's sassy twin sister Ursula (both played by Lisa Kudrow).

Other Friends characters simply drove viewers insane for all the wrong reasons.

Remember Rache's love interest Tommy - famously portrayed by Ben Stiller - and his sudden bursts of anger? Boy, was he a nutcase.

And don't even get me started on Ross' uber-controlling British wife Emily (Helen Baxendale), who notoriously tried to stop him from seeing Rachel.

Still, there's one character we're missing from this list who famously had viewers sitting at home tearing the hair out.

And ironically, part of his storyline was about how much he agitated the other six main characters.

Roger was a love interest of Phoebe (NBC)

We are, of course, talking about Roger the psychologist, who was introduced as a love interest of Phoebe all the way back in the first series.

On the show, Phoebe is devastated to hear that her best friends - Chandler, Joey, Rachel, Monica and Ross - can't stand the man she's dating, even though she's head over heels for him.

Though the group try their best to see past Roger's intense assessments of their lives and eerie mannerisms, they tell Phoebe they can't, before she tells him.

Roger then unleashes a savage soliloquy about how much he hates her friends back, prompting Phoebe to dump him and declare, 'I hate that guy!'.

Apparently, however, Roger didn't just grind the gears of the cast whilst filming, but the actor behind him - comedian Fisher Stevens - also made several enemies during his time on the show.

And only recently did he admit to this dubious behaviour, issuing an apology for to the rest of the crew and confessing he was 'kind of an a**hole'.

Stevens has since apologised for his behaviour on the show (JC Olivera/Variety via Getty Images)

Appearing on an episode of People TV's Couch Surfing, Fisher claimed his co-stars couldn't hide their resentment towards him.

"Yeah, I'm sorry guys," he spoke out. "I'm sorry I was a d**k to you all.

"I apologise. I was bad, I was wrong."

Fisher also went on to claim that his behaviour was caused by a lack of understanding about what Friends was really about, being that his scene featured in the show's earliest days.

Recalling that he didn't handle changes to the script very well, he told viewers: "'What do you mean? So I have to relearn lines that you've written that are worse than what you'd originally written?' Yeah, I was a d**k.

"I've rarely seen any of those people on Friends again, but I'm sure if you asked them about me, they would go, 'What a New York snob.'"