<p><br /> It seems the Ultimate Big Brother house may be proving a confusing place for some of the contestants.<br /> </p><p><br /> Nikki Grahame may be 28, but perhaps a little refresher course in the birds and the bees wouldn't go amiss.<br /> </p><p><br /> Nikki's confusion arose during a conversation with Brian Dowling about fellow contestant Nadia Almada's slightly moody behaviour.<br /> </p><p><br /> Nadia was born a boy, but had a much talked about sex-change operation before winning the fifth series of Big Brother in 2004.<br /> </p><p><br /> Despite overwhelming anatomical evidence to the contrary, Nikki's explanation for Nadia's moodiness was simple: "Maybe Nadia is on her period?"<br /> </p><p><br /> Ever the diplomat, former airline steward Brian left a pregnant pause before replying: "Yeah... unlikely, but maybe."<br /> </p>
