Are you feeling nervous about the show?
Charlie: "I am."
Lulu: "He's too perky for my liking!"
Charlie: "I'm turning it on - it's tears of a clown. I've been nervous. I've not slept, really. I've been dreaming steps - anxiety dreams of people chasing me with dance moves."
Lulu: "Dance shoes! Legwarmers!"
Charlie: "Are you nervous, Lulu?"
Lulu: "I think it comes and goes when I get overly serious about it. But when I'm actually rehearsing and it's fun, I want to remember that. When you're on live TV, sometimes you can get caught up in your own ego. But it would be great to realise, to remember why I'm doing it. And it's fun. It's a great way to exercise. I think dance is the best exercise for anybody because it does make you feel happy. So I hope I don't get nervous on the night."
Charlie: "That's what I think. What's the point in getting nervous? But then I think, 'Ooh, I'd really like to get it right!'"
Lulu: "I want to be good."
Charlie: "And I picture myself falling over into a camera."
Lulu: "Tripping up a dancer!"
Charlie: "Punching a judge. By accident, of course."
Lulu: "Now that would be funny."
Are you taking it quite seriously, then?
Charlie: "You have to take it seriously in training, because otherwise you don't learn it. I'm not taking the competition element seriously. I'd just like to get it right on television, because now with the internet it's around forever."
Lulu: "And you hope it's a good show that people say, 'Wasn't that hysterical? Wasn't that a laugh? Can you believe they did that?' And for people to phone in and get the money in. So you want to do it well from that point of view. But definitely if you can have fun as well. That's what the show says - watch these idiots make fools of themselves."
Charlie: "I'm backing Lulu to win though. That's it - I've blown it. I've said it out loud now."
I was going to ask who your biggest competition is.
Lulu: "He hasn't even seen my dance so he's just talking out of a hole in his butt."
Charlie: "I've seen Lulu do her Swan Lake dance! Her dying swan brought me to tears!"
Lulu: "Natalie Portman, pah! I haven't seen anybody's dance. Definitely the comics are my biggest competition because it's about comics."
Charlie: "But no-one knows who anyone is, except Noel Fielding."
Lulu: "Does that really matter? I don't think [fame is] what helps them win. I think it's about the fact that they're funny. The people who have gone before, like Russell Kane - you went, 'Oh my God, it's great', then you laugh. It was funny and it was great. It was ridiculous and it was great... The shock value of it all - it's all entertaining. It's not brain surgery."
Are there any moves in your dances we should look out for?
Charlie: "My four backflips that I do."
Lulu: "Are you doing four backflips as well?"
Charlie: "I can only do four!I know you've got the five in but listen, we've not all got that in our locker."
Are you hoping to get through, even though it will mean you have to perform again?
Lulu: "Oh God, yeah. You all fight to win. Hopefully it's not cut-throat."
Charlie: "With Lulu I'm going to be a bit... Do you remember those ice skaters? I'm going to be a bit like that beforehand. I've employed someone - Big Harry, he's called. And he's coming round to Lulu's house with a cricket bat in the morning. That's how seriously I'm taking it."
Can you tell us anything about your costumes?
Charlie "I don't think I can. It sort of gives it away. I think it's nice that it's a surprise. Our VT doesn't match up in any way to our dance, so it's nice they throw people off the scent. I think if you knew what we were going to do it takes that surprise element away completely."
Lulu: "I agree. And they've been a great team to work with. It's an institution, this charity. It achieves so much."
Charlie: "It's great to work with the professional dancers and the choreographers because they're so skilled and so talented. To work in a different field of expertise and see people who've got a proper skill..."
Lulu: "You realise they deserve a gold medal. They're unbelievable dancers and they work harder than anybody in any walk of life. Dancers are the hardest workers."
Charlie: "They're so fit. I turn up and I haven't danced in 20 years, and it's like 0-100 in day one. We're flat on the floor breathing and the dancers are like, 'Shall we do it again then?' We've been doing it and then our choreographer's been showing us his version of it, with all better moves."
Lulu: "I just want to beat [my choreographer] Gareth."
Charlie: "I try and console myself with, 'Well, you go and do ten minutes at the Comedy Store'."
Lulu: "I can't do that because Gareth can sing."
Have you picked up any injuries during your rehearsals?
Charlie: "James, who I'm working with - he got run over a year ago so he had a broken leg and a broken knee and all sorts of stuff. It's absolutely amazing what he's doing. I'm like, 'Careful of your leg, mate!' Our dance requires quite a solid floor and the place where we've been rehearsing hasn't had quite the right flooring. So we both hit the deck a few times and every time we go down it's like, 'Oooh...' It's like the footballer in the semi-final - 'Oh, he's going to miss the final, he's missed the final, that's it, you're out'. And secretly a bit of you goes, 'Ooh, I could do this on my own!' No, it doesn't."
Lulu: "Every single strand of hair on my body aches. Everything aches, because I've been giving it gusto."
Charlie: "But next week you'll be going, 'Oh, I wish I was dancing on that'."
Lulu: "Yeah, because I think you get the adrenaline rush. I think in this business, you become a bit of an adrenaline junkie. You go up on stage, you get the applause, you try something different and you get a real buzz from it. So cold turkey next week!"
Why did you want to do the show - was it the Comic Relief factor?
Charlie: "Yeah, and just to dance and do something different for a week. And it's Comic Relief. For me personally, it's good to be on telly as well. I can't hide that it is good for me to do it."
Lulu: "I watched it and I thought, 'It's funny'. And I thought, 'It's once. And if you don't get to the final you've just got the one, and if you get to the final you just do it again'. It's not every single week."
Charlie: "I don't know what it is about dancing... It's the one thing you watch as a punter and go, 'I'd like to do that'. I don't watch the ice skating show and think, 'Ooh' or any of the singing ones and think, 'I want to do that'. But the dancing looks great. And it's timeless... it's a proper skill."
Lulu: "I'm sure most people think, 'I think I could do that'."
Charlie: "And then you get to it! 'You know I was drunk at a wedding and said I could dance? Watch this!'"
Lulu: "Actually at my age I think it's a challenge. I'm a grandmother, I'm 62. I always liked to challenge myself, so it's a big challenge to last the rehearsals, let alone get to the show!"
Charlie: "That's Lulu going for the grandmother vote and over 60s vote."
Lulu: "The demographic for this is only 18-45!"
Charlie: "Bad luck. Because I was going for the grandma vote - I was going for the 'Ooh, he's cheeky, I like him' vote. So we're going for a similar vote! I'm just going to go and call Big Harry..."
Let's Dance For Comic Relief airs tonight at 7pm on BBC One.
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