
Over ten million viewers watched as bubbly Kirsty Docherty, 24, from Clackmannanshire, Scotland, threatened the head judge with her mean jail officer stare on the hit ITV talent show and then got put straight through to the next round.
In an exclusive interview, Kirsty told the News of the World she dreading the reaction from the murderers and rapists at HMP Glenochil where she works.
She said: "When the prisoners see me give Simon my evil stare I know they are going to absolutely slag me to death.
"I talk to the prisoners and they all know about the show, every single one. You can't keep a secret in there. The minute someone in the jail finds out something it spreads and every prisoner knows about it.
"They have TV in their rooms so they were all planning to watch it and bang on their doors when I was on. That's what happens when there's a big football match on, they all rattle their cell doors."
The inmates are also likely to be jealous of the attention showered on buxom Kirsty - who impressed by belting out I'm Sorry For Blaming You - by Simon.
She revealed: "You didn't see me in this in the show but after I performed Simon actually asked me to come back in my prison uniform. I think he got off on it. He likes a dominant woman.
"I told him that if he didn't put me through to the next round I would come back in my uniform anyway. I think he was a bit threatened by that."
She added: "Simon also said to me, 'The prisoners must love you.' I told him they really didn't! When I told him there were lots of girls that worked there he got really excited and said, 'Really?'
"He couldn't believe so many hot young girls would work at a male establishment like that."
But Kirsty said it's Dannii Minogue and Cheryl Cole who the crims are interested in, rather than Louis Walsh or Simon.
"They are completely obsessed with Dannii and Cheryl. One prisoner asked me to steal some of Cheryl's underwear if I got to go to her house for the next round. Another wanted me to give Dannii a kiss for them.
"Cheryl wanted to find all about my job but Dannii just couldn't even imagine doing it. If they had to do my job in the prison for a day I think the girls would be absolutely petrified.
"I think Simon would be more popular than Louis would be, I think he'd probably annoy them.
"But even Simon would get his comeuppance if he had to walk in my shoes. Obviously he's a really powerful man in the business that he's in but he'd be more scared than ever if he was in there."
Kirsty has worked at the prison for two-and-a-half years since graduating from university.
She said: "I wanted to work with criminals in some capacity so I thought I should just join the jail.
"It was definitely threatening when I first started. You're not actually in a prison environment until your first day. They expect you to get on with the job as soon as you're there and you're handed a set of keys.
"You spend time by yourself with the prisoners but you've got a personal alarm if anything happens."
She added: "I've never actually sang for any of them. When I walk by they often yell, 'Give us a tune.' But none of them have heard me.
"I'm very happy in the prison at the moment but I'd leave in a second if it meant I could launch a pop career. I've always sang and that's my main passion."
