Lily Allen stunned concertgoers at Koko yesterday, when she joined Professor Green on stage for an impromptu performance of their song ‘Just Be Good To Green’.

Having kept a relatively low profile of late, Lily’s five-month bump was looking a great deal larger than when she was last spotted gracing the front rows during London Fashion Week.

And proving she’s not one to go for the more traditional maternity wear, the blooming star hit the stage in a metallic empire-line minidress, leopard print cardigan and impossibly high heels.

The 25-year-old, who is expecting a boy with beau Sam Cooper, has admitted to having a ‘really stupid list’ of baby names.

‘The whole thing became a lot more real to me when I found out it was a boy,’ she said in a recent interview.

‘You start to think of names, and then you can go shopping, and it all feels like it’s happening.

‘I’ve got a really stupid list of names, but I’m not going to show you. But, no, we probably won’t [use it] – I think Sam is way too straight and traditional for that sort of thing.’