The teenager won a spot in Saturday's final after topping the public vote on last night's latest semi-final show.
But Sam revealed this week: "My fan base has always been older, but now I seem to have loads of teenage fans.
"I visited my old school and was screamed at by 300 girls wanting my autograph. I've had a lot of girls proposing on twitter as well, it's bizarre."
But despite his new heartthrob status, Sam insists he's not the new Harry Styles!
He added: "I can't imagine living the rock star lifestyle - I'd be terrible at it. One direction look like they're having an amazing time, but I'd prefer to be with one girl for a long time than loads of different people."