Pregnant singer Mariah Carey and her actor husband Nick Cannon have posed together nude in a series of photos which they plan to put up on the walls of their home.Carey, 42, is due with twins May 14. But Cannon, 30, confessed he is not so sure it was a wise decision, reports usmagazine.com.'My children are going to have to see these pictures. It's a little weird,' he remarked.'It's a little nasty,' the 30-year-old continued. 'I mean, have you ever seen your parents naked?'When they get older and their friends come over... they will see the pictures and say, "Your daddy's butt naked."'The pop diva also recently tweeted a picture of herself with a butterfly painted on to her impressively-sized bump.