Simon Pegg and Thandie Newton: Serious About Comedy

In the comedy film “Run Fatboy Run,” Simon Pegg plays a commitment-phobic slacker named Dennis who enters the London Marathon in hopes of winning back his ex-girlfriend Libby (Thandie Newton), the woman Dennis deserted at the altar. Pegg, 38, and Newton, 35, sat down to discuss the movie, the downside of being a celebrity and what kind of naughty pranks they played on each other.

How was the chemistry between the two of you when you first met?

Newton: I think that as far as the chemistry goes, it was good that we were at odds for most of the film … It was such a lovely atmosphere on the set, the challenge was to not enjoy you.

Pegg: Thandie’s aggressive technique in us getting to know each other was to play jokes on me, which she did on a daily basis. I began to fear entering my trailer. I was like Inspector Clouseau waiting for Kato to jump out. I’d go in there and there’d be squashed-up chocolate bar in my toilet that she’d kindly squished into … fecal matter.

Newton: And an old pair of underwear of my dad’s. I’d smeared Marmite into the butt crack of the underwear and dropped it next to the toilet bowl. So there was that, and the Mars Bar poo, which was a prank and a snack. And I got some hair out of the wig I was wearing and left it with the poo.

Pegg: And that was just day one. I came in one day and the neck of my sweater was sewn up. She’d gone in, spent time in my trailer, weeping with laughter as she sewed it up. It was baffling to me. I kept thinking, “Where is this statuesque, awfully serious Hollywood actress I’ve been hearing so much about?”

Newton: Yeah, I don’t know what’s happened to me in the last 10 years. Something’s happened for sure. But the façade has come down.

Pegg: In all seriousness, it completely put me at ease. For someone who had not worked with Thandie before, I got the measure of her right away. I realized that she wasn’t poker-faced or overly serious, and that made for a great relationship on set.

What was it about the “Run Fatboy Run” script that appealed to you?

Newton: [to Pegg] Well, you did a huge amount of work with it, didn’t you?

Pegg: I rewrote it from Michael [Ian Black’s] original script, which was pretty much there. I had to translate it to the London setting. I love things that challenge me. And it was the idea that this guy, who is fairly ordinary-looking and overweight, jilts his beautiful, pregnant bride on their wedding day and he’s the hero. For me, that’s something I want a part of. I mean, how can you root for a guy like that? How can you make him sympathetic? Someone who’s done something so awful.

Simon, you lost a lot of weight for this film and had to run around wearing prosthetics to make it look like you were heavier than you really were. How was it running around under all that extra weight?

Pegg: Actually, it was a godsend. We were filming in December in the U.K., and it was pretty cold, so I was insulated by my little latex buttocks … It was like a wet suit, with boobs, a tummy and a muffin top. It was actually all right. It kept me warm.