The couple, who split in July, had been together on and off for five years before going their separate ways.
'I know he's been very public about trying to get me back, but we're still not together.'
The formula 1 star dedicated a recent win to Nicole and has also been very vocal on Twitter regarding his emotions post-break up.
Nicole, 35, who will reprise her role as X-factor judge next week said the dedication was 'sweet of him' but that she prefers to 'stay in the background.' She added: 'it's nice to be acknowledged and to know that someone realises the support they had.'
The ex-Pussycat Doll has also been very candid about her break up with Lewis, admitting: 'I'm just like every other woman, I've had a blanket of tissues over me many a night. Ordered a random, ginormous pizza for myself.'
In the interview with Glamour magazine, she also said: 'I definitely have my dark moments but I wanna be a light,' adding 'sometimes, when you're sad, you bring the pizza and you make that choice.'