Tell us about Saturday's SYTYCD final.
"I'm really excited about Saturday's final. I think the two boys are going to kill it. And kill each other possibly in the process! I'm pleased with the final four. I would have loved to have seen Bethany Rose rather than Kirsty, but that was the public's choice. I think it will be really exciting on Saturday. Kirsty is clearly well loved by the public and I think that Katie Love will have a battle to match her for performances. But we have great choreographers in and it's going to be a challenging, challenging final."
You said that you wanted the show to be sexier this year. Have the dancers achieved that goal?
"Yes it has. I think the programme has everything from wholesome to sexy. Dynamic pieces and sensual pieces. It's been a rollercoaster run this series."
At this stage in the competition can one great dance win it or will audiences have already made their mind up?
"We never get to know who is the top of the voting. We only know who the bottom two or four are. I've always thought Matt Flint from the start would win, He's so good, he's so cheeky, he's so charming, he's such an all rounder - he has it all. I've always thought Matt might win and he may do one phenomenal number, but I just don't know. If Luke does something that just defies dance...and Katie Love last week in her duet, the Mandy Moore duet - wow! From the moment she started to dance, for the first time this series, I had goosebumps. When you see exquisite and almost perfect dance, as a choreographer, I wanted to get up immediately and work with her. It was extraordinary. So it could be anyone's game."
You had a big bust-up with guest judge John Barrowman. Did you kiss and make up?
"It was quite extraordinary. I didn't know that was going to happen. I was angry that he could come in for one week and start talking like he is the expert on Broadway. I'd like to challenge him on the amount of Broadway shows that he's seen to the amount of Broadway shows that I've seen. Also, he has no knowledge of experimental dance, new Broadway and everything that's going on there, which very much comes from the contemporary dance world. John doesn't know anything. He is very much still in Anything Goes. He first did that in the 1990s or maybe even the 1980s. He did get my hackles up."
Do you often keep arguing backstage with the other judges?
"When I care passionately, I do. I have done with Sisco and I certainly did with John. I don't argue or shout, I just say, 'Before we go home, just so I can sleep at night, please let me explain'. I do it in a very calm way. When I have an argument I can't just leave it, I have to get my point across."
Have you been disappointed by the slide in ratings this year?
"Everyone can talk about ratings and generally I avoid talking about them. But I'm very surprised. I'm not sure it's a show to put on at 5.30pm. But even last week we got low viewing figures. Is it to do with sunshine? Probably not, because if you really want to watch something you will. The thing is that our online viewing has been incredibly high. Hits on the website have been extremely high. The problem, for me, is that I drop off watching anything when the time moves around. Is it 6.15? Is it 5.45? Is it 7.30? Is it 8.00? You just give up."
That always annoys me with big shows like this as well.
"I remember one year doing Strictly where they dotted it around and Brucie was saying, 'And don't forget, next week's show is on at...'. I just thought, 'How will people remember?' It's 6.00, then it's 7.00, then it's 6.30 the next week. I find it quite confusing. What are you going to do? Write it down and put it in your handbag. People need a time. It's always disappointing with ratings, but I don't know why they are down. You can ask yourself and question yourself... but even my oldest daughter watches it on catch-up. She comes in late on Saturday night and watches it online. She doesn't ever rock up at 5.30pm and watch the show live even though her mum is part of it. But Nigel takes it all in his stride, it's his show, so we should all take it in our steps."
The show is huge in the US. Why do you think it hasn't made the same impact here?
"This is all about attaining something of a high standard. This isn't about the jokers, which other reality TV shows deal with. What's really interesting is that at the SYTYCD auditions, we don't get people turning up for fun. We get people who know what the show is and they want to be part of it. I don't know what the demographic is in America. It doesn't go out on a Saturday there so there are a lot more people at home. I don't know what the demographic is in terms of ages, but certainly in the UK, Saturday night entertainment has become about the family. It's not teenage viewing time. So there's probably a demographic issue. I don't know what the British public want. It's very, very hard to say. Had the show been on at 7.30pm every night would it have made a difference? I don't know. I just know it's a fantastic show and a really important show for the BBC. It brings young people into watching telly and that's important."
Is there any chance you might return for a cameo on Strictly this year?
"No, I've been asked to do that and I said no. No."
Why is that? Do you want to move on from it?
"I just don't. I just don't. I don't want to have to do it. I don't need to. I don't want to."
Where can we see you on TV next?
"I've been turning a lot of stuff down for television because it doesn't feel right. Don't ask me what I think is right for me, because I don't know. But I certainly know what isn't right for me. So I'm doing a lot of saying 'no' at the moment. But I'm sure something will come up, where I'll be running and jumping and saying 'this is the perfect choice'."
The So You Think You Can Dance final airs on Saturday at 7.15pm on BBC One.