The pair played father-and-son Martin and Adam Goodman in all six series of the Channel 4 sitcom.
Following the news of Paul’s death, Simon has now shared some poignant memories of their decade working together, in a thread posted on co-star Tom Rosenthal’s Twitter page.
Tom explained: “Simon’s not on Twitter but wanted to get a message out about Paul so here it is.”
The thread then began: “Not even going to touch the acting. That goes without saying. He was the best in the business.
“What’s less well known is that he was also the Platonic ideal of a green room companion: unfailingly generous (with praise, snacks, the Guardian Sport section); unendingly thoughtful (he would set up shop on the floor if he knew there were going to be more actors than chairs in that day); and undeniably cool (calm and collected in his flat cap, but an absolute coiled spring if there was a game in the offing).
“He was such a peaceful presence but throbbing with intelligence and - let’s not beat around the bush - entirely capable of a hilariously indiscreet and filthy broadside when in the mood.
The Inbetweeners star added: “I think I’ll always aspire to be like Paul. I guess that’ll happen when someone pretends to be your Dad for 10 years.
“I feel unbelievably fortunate to have spent so much time in that green room and hope his real bambinos know how much his fake bambinos loved and looked up to him.”
Paul’s on-screen wife Tamsin Greig also paid her respects in a piece in The Guardian earlier this week, writing: “When I was told that they wanted him to play Martin Goodman in the pilot episode of Friday Night Dinner, I said: ‘You get him and I’m in.’
“Not only did Paul deliver in the role, he far surpassed everyone’s expectations – surprising, versatile, oddball, rooted in the clearest truth and always utterly, heart-stoppingly hilarious.”
“The world is a less brilliant place without Paul in it. Go lightly, my friend. You are deeply beloved.”
Paul and the rest of the Friday Night Dinner cast recently completed filming on a retrospective special, in honour of the show’s 10th anniversary, which will air on Channel 4 later this year.
It’s since been revealed that the special will be dedicated to his memory.