Jonathan Watson reveals that one day he got the most painful giggles on set...

How would you describe your character, Colin?

Colin is a well-meaning fool. He just finds it very difficult to resist the temptation to indulge in a bit of one-upmanship, and it could be about anything - a job, a car, a kettle. And he doesn't even know he's doing it now. It's part of his make-up.

I think he'd be horrified if he thought people didn't like him. He just wouldn't be able to understand why.

What's his marriage to Cathy like?

He's devoted to Cathy and would do anything to keep her sweet - a bit like my marriage actually!

They share the same values, they are very much like two peas in a pod because she equally likes to brag.

How does he feel about his Latimer Crescent neighbours?

He really likes them and would probably do anything he could to help them in a crisis, although he'd moan about it later.

He thinks he's a wee bit better than Beth and Eric. He's not being nasty - as far as he's concerned, that's just a fact of life. He has a better pension than them and that's not his fault, it's just the way it goes. He does like Christine, but sees her relationship with Sophie as a little warped.

Would you describe Colin and Cathy as the neighbours from Hell or Heaven?

I would say Hell. Can you imagine living next door to those two and they're in and out of your house all the time? It'd do your nut in!

Colin and Cathy seem to make themselves at home with the Bairds a lot - why?

It's just this thing they do, they feel quite comfortable to just walk in unannounced. I'd absolutely hate that. I don't think it bothers the Bairds - it's just the relationship they all have within their little community.

That being said, I'm not sure they'd just drop in on Christine like that. I mean you don't know what she could be doing in there. She could be changing... something. Colin couldn't begin to imagine what he'd find if he just walked in on Christine.

The bottom line is the neighbours are all polite enough to like each other. Over the course of events, they slag off each other but they'd be there for each other if needs be.

Any memorable moments from filming?

I don't usually 'corpse' or anything like that, and it doesn't happen a great deal because of tight filming schedules. But there was one day when Alex, Elaine and I absolutely got the most painful giggles on set.

Elaine had to deliver this line to me, and Alex was to come in quietly carrying a tray with crockery on it. Now, that's not easy, and we'd hear him come in with a clink and that would set us all off. We were crying with laughter.

I'm the one that's known for mimicry, but Alex Norton does the finest James Mason impersonation - he's absolutely brilliant at it. After a take I'd say to him "was James happy with that?" and he'd put on his best James Mason voice. I used to love it.

Elaine C Smith is a new addition to the Two Doors Down cast - what was it like filming with her?

I've known Elaine for a long long time and we were at drama college together. Over the years, we've worked together a lot in shows like Naked Radio, Naked Video and various theatre productions, including a panto which Alex Norton directed. For the first 10 years of my acting career, we worked together quite a bit, but it's been 17 years since the last time we worked together. She's just perfect as Christine.