Casting for the highly anticipated X-Men spin-off is so hush-hush that even obsessed fans know only that Hugh himself will appear.

But the main reason for all the secrecy is that it'll be his actress wife Deborra-lee Furness who'll be giving him a thumping - and he won't know a thing about it until the cameras start rolling.

'It'll be a complete shock for Hugh when Deborra-lee appears on set,' a close friend of the couple says. 'He won't know what's hit him! The idea is to catch the look on his face when he realises it's his wife who's about to beat him up for the benefit of millions of movie fans.'

Aussie Deborra-lee, 47, was sceptical when producers came to her with the idea. The mum of two was mildly horrified at the idea of dressing up in a bikini-type superheroine outfit, which is a far cry from her usual roles.

But now Deborra-lee thinks it'll be a great laugh and she's looking forward to being part of the practical joke.

'She can't wait to see the look on Hugh's face when she turns up for filming,' an insider says.

The scene in which Deborra-lee will appear will show her sultry unnamed character lure Wolverine into an ambush then mercilessly attack him before he finally escapes her evil clutches.

'Deborra-lee was talked into it as a great idea for the DVD when it goes on sale because they can show Hugh's reaction as an out-take,' the source says.

'The bikini idea was a bit of a stretch though and she drew the line at that, ordering the costume department to come up with something else that is suitably slinky and sexy.

'But she'll have martial arts training to be in perfect shape for when filming begins and, no doubt, look as absolutely stunning on-screen as Hugh will look absolutely stunned when he claps eyes on her.'

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