The former couple recently broke up and are said to be making sure they don't cross paths at the event in London this weekend.
According to reports in the Daily Mirror newspaper, the pair devised a plan to ensure they could both attend the festival without meeting awkwardly after their split.
While it was agreed Lewis would apparently be on-site for Justin Timberlake's headline set last night (12.07.13) and Jay-Z's tonight, it is said the former Pussycat Doll will see the pair close the festival with a joint performance tomorrow.
Explaining the choice, an insider revealed: ''Nicole's a massive fan of Jay-Z and really wants to see him. She has a busy schedule and so Sunday was the only day that she could do.''
Both parties are struggling through the break-up, according to recent reports, with the Formula 1 driver admitting he is finding it ''really, really tough''.
He previously said: ''I'm going through... I'm trying my hardest to be positive but I'm going through a really, really tough time at the moment with the loss of someone really, really special in my life.
''My world's turned upside down, but I have a job ... So I'm really trying to pull myself together and keep my head up, but it's so hard to do.''
Meanwhile, Nicole revealed she is also struggling to cope with their split and said it ''really sucks''.
Perry performed 'Rise' and 'Roar' before Clinton accepted the nomination to be the Democrats' presidential candidate.
Bruce Springsteen will release rare tracks from 1966 in new album 'Chapter and Verse', which will accompany his autobiography 'Born To Run'.
There's still no reunion planned though.
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