The pair, who were rumoured to have been dating, are said to be planning to visit Derek's mum, Marianne Nelson, in Nevada, and the head for a tourist trip to Sin City.
A source told The Sun, 'Cheryl's only been to Vegas once before and didn't get to spend much time there so she's really looking forward to it.
'She has already made a list of things she wants to do and said she wants to just be a 'tourist' and do all the tacky things people do there.
'She wants to see some shows and have a flutter on the roulette.'