Big Brother stars Nikki Grahame and Imogen Thomas were spotted together enjoying a catch-up in the sweltering heat.The two reality stars, who appeared together in the 2006 Channel 4 series, reunited over drinks as they were seen walking down the street smiling away. Both Nikki and Imogen have recently returned to the spotlight thanks to E4's re-runs of classic moments that have been aired in a Best Bits series to celebrate its 20th anniversary.