Susan Boyle stunned friends and family after launching into two four-letter rants within hours of each other.
wind her up provoking Susan to roar back at them: How f**king dare you! You can't f**king talk to me like that.
The 48-year-old spinster - who has become a worldwide star following her performances on 'Britain's Got Talent' - initially lost her cool when watching 12-year-old rival Shaheen Jafargholi perform in the semi-finals of the show in Tuesday night (26.05.09).
Susan was furious when judge Piers Morgan - who she has admitted having a crush on - praised the Welsh boy by saying it was the best singing performance so far.
Onlookers claim Susan, watching the show at a hotel bar, screamed "f**k off" before sticking her two fingers up at the screen and storming off.
One said: "She was clearly upset that her favourite judge had sided with one of her main rivals. It's beginning to look like it's all getting a bit much for her."
The following day, the Scottish singer had to be calmed down by police after she got involved in a heated argument with two strangers.
Sources reportedly admitted they had been trying to "wind her up" provoking Susan to roar back at them: "How f**king dare you! You can't f**king talk to me like that."
Two police officers - who were on duty at the London hotel all the 'Britain's Got Talent' contestants are staying at - then went up to ask if there was a problem.
With tears streaming down her face, Susan replied: "Of course there's a f**king problem" before storming off.
Her friends have now warned her she needs to control her temper if she wants to keep her fame.
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