Samantha MarchantSam MarchantThey haven't been out of the Big Bro House for five mins...

But already Sam and Amanda Marchant have done something unusually classy for BB wannabes.

The twosome were invited to take part in a catwalk show in aid of Fashion For Relief.

They were joined by a bundle of other celebs on the catwalk, including Christian Slater, Jamelia, Patsy Palmer, Rio Ferdinand, Princess Beatrice and her mum Fergie.

There were also a good helping of professional models, including Lily Cole, Yasmin Le Bon, Lizzie Jagger and Naomi Campbell to show them the ropes.

Fashion For Relief was set up by Naomi in 2005, to help victims of Hurricane Katrina.

Naomi Campbell on the runwayNaomi Campbell on the runwayHowever, this year, the funds from the event are going towards helping those hit by the summer floods in the UK.

See all the runway action - and spot some big name models just chilling out in the audience.