The 35-year-old singer and the Formula 1 driver called time on their five-year on/off relationship because they barely got to spend time together due to their hectic work schedules, and the 'X Factor' judge opened up for the first time during auditions in Cardiff on Wednesday (03.07.13).
After watching a wannabe perform an emotional song, Nicole said it ''pulled on my heartstrings'' and then empathised with the teary tune's lyrics about the end of a relationship.
She said: ''It sucks doesn't it? Really sucks.''
Despite feeling moved, she enjoyed the song, adding: ''It's so depressing but it's so good. I would buy your album.''
Following the poignant moment, Nicole - who turned 35 on Saturday (29.06.13) - put on a brave face during the auditions, and at one point she showed off to her fellow judges Gary Barlow, Sharon Osbourne and Louis Walsh by performing the splits.
An insider told The Sun newspaper: ''Even though Nicole is going through a tough time she was determined to get on with things. Throughout the day she was showered with presents from contestants after celebrating her 35th birthday during the week.
''She really appreciated that and she even impressed her fellow judges by doing the splits during a break in auditions.''
News of Nicole and Lewis' split materialised earlier this week, but insiders say the pair broke up around one month ago.
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