The X Factor champion Matt Cardle has exclusively revealed to MTV UK what was going through his head when duetting with superstar Rihanna, but you might be a bit surprised by his answer.

We caught up with the 27-year old, who looks set to be this year's Christmas No.1 with his version of the Biffy Clyro track When We Collide, to find out what it was like singing with RiRi.

Speaking about his finale duet with the Barbadian beauty, Cardle joked: "I was actually thinking just don’t get an erection. I had very thin, very soft trousers on and I was like 'please, please, please'. I was thinking "Margaret Thatcher, Margaret Thatcher."

He continued: "There was no a chance in hell that was going to happen to me at that stage though. I was just too nervous! (The duets) are just so weird and different. You can't prepare yourself for it and Rihanna got awfully close."

While on the subject of the What's My Name singer, Matt also admitted that he would love to work with Rihanna again, stating: "She called me on the Sunday night, I don’t have her number but she called my tour manager to congratulate me."