And as soon as the blonde rapper sat down on his sofa, plenty of juicy details about their frosty relationship came tumbling out.
The singers have been at loggerheads ever since they first started working together on American Idol.
Nicki wore a garish trouser suit for her appearance on the show, which Kimmel immediately commented on.
‘Where do you get stuff like this? Do you have to make it?’
‘No!’ she said, ‘It’s Roberto Cavalli, you can buy it in stores.’
He went on to praise her judging skills on the talent show, saying that she seems solid and reasonable, which is the opposite of her public persona.
‘A lot of people don’t like their co-workers at their offices, but your office is on television and so when you have skirmishes everyone sees them. And clearly, you and Mariah Carey do not like each other,’ he probed.
‘I wouldnt say I don’t like her, I definitely don’t think she likes me,’ Nicki replied, adding that despite this, she makes a fair bit of effort to be friendly.
‘I try, as I looked up to her for a long time, so I don’t want to hate on this lady, but she had an issue from the beginning. We’re having fun though.
‘I genuinely like going there, even Mariah and I, we really do have fun.
But while she might be making waves on reality TV, Nicki was there to do what she does best – perform.
She took to a special outdoor stage to perform Va Va Voom and Freedom in front of an overexcited audience.
Writhing and singing to the music of a live band, Nicki added a jaunty leopard print hat to her already clashing outfit.
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