Professor Green is thrilled Lily Allen has announced her pregnancy – because he couldn’t keep it a secret any longer.

The rapper has become firm friends with the pregnant pop star over the past few months, after Lily agreed to feature on his track ‘Just Be Good to Green’, and he admits it was getting hard for him not to tell people the news because of the amount of concerts Lily was cancelling.

He told BANG Showbiz: “It was hard. Everyone was asking me why she kept pulling out of gigs and all I could say was, ‘Oh she’s sick.’ I’m so glad everyone knows now.”

And the 26-year-old pop newcomer – who first met Lily after they were introduced on social networking site Facebook by mutual friends – has joked he is going to buy Lily’s baby “a Rolex, like she got me”.

Although he is happy for Lily and her boyfriend Sam Cooper, Green – real name Stephen Manderson – isn’t ready to have kids of his own any time soon.

He said: “I wouldn’t consider getting pregnant any time soon and I’m not thinking of getting anyone else pregnant either!”

Lily Allen wasn’t ready to smile for the cameras as she banned photographers from taking pictures of her onstage during her final gig.

It was certainly a rather dressed down Lily who took to the stage at the Big Chill in Herefordshire which may explain why she wasn’t keen to be pictured.

Lily arrived early on stage in a pair of jeans, huge checked shirt and Converse trainers after chilling during the day with boyfriend Sam Cooper.

She said: ‘Excuse my casual attire but I’m pregnant and this is called the Big Chill.

‘I packed high heels but my boyfriend unpacked them. He told me I’m not wearing high heels on stage. So that explains the jeans and lumberjack look.’

Her dowdy outfit was more suited to a day in the park rather than for a pop star entertaining thousands.

While fellow artists M.I.A. and Paloma Faith were photographed in action on the stage, the snappers had to vacate the press pit for Ms Allen’s set at 10:30pm.

A spokesman for Idea Generation, the PR firm handling the Big Chill, told MailOnline they were only told on Sunday by Lily’s management that she wanted a blanket ban on all press photographers while on stage.

This was a strict ‘condition’ of her performing at the event.

Her performance at the event, held in sprawling grounds of Eastnor Castle Deer Park in the Malvern Hills, marks what is likely to be her last live gig after announcing she is taking a five year break from music.

She kicked off her set with LDN and Everyone’s At It and 22 from her second album, before finishing with an encore of It’s Not Fair.