By Jasmine Allday One Britain’s Got Talent contestant left the judges lost for words with an X-rated blunder on the show. Sven Smith, 27, kicked off the third episode of auditions by performing an air guitar routine to a medley of Queen songs. The judges loved it including Simon Cowell, who said he was feeling “ecstatic” by the performance. The air guitarist got the whole of the venue up on their feet as he danced around the stage and impressed Speaking as they gave him their feedback, judge Bruno Tonioli began by saying: “I don’t know how to describe that. I think your pants nearly fell off,”…