Kanye West forgot the words to his own song at Kris Jenner's birthday party.

Kanye West

Kanye West

The 38-year-old rapper was passed the mic by singer Charlie Wilson, who was singing his tune 'Outstanding' before breaking into Kanye's 'See Me Now' - on which he performed with Beyonce - but he admitted he could no longer remember the lyrics of the 2010 single, and quickly improvised with one of his rival's tracks instead.

A source said: "Kanye said, 'I don't remember the words!'. So he started singing 50 Cent's 'In Da Club' instead. The whole crowd was chanting [the song's lyrics], 'Go Shorty! It's your birthday!' "

Kanye - whose wife Kim Kardashian West is expecting their second child - then led the guests at the bash at The Lot in West Hollywood in a rendition of Stevie Wonder's 'Happy Birthday'.

Later in the evening, birthday girl Kris - who turned 60 on November 5 - made a lengthy emotional speech.

The source added to the New York Post newspaper's Page Six column: "Kris made a toast and thanked everyone. She was very emotional and it seemed to go on forever, but Khloe grabbed the mic and screamed 'the speech is over!' "

As well as Kris' famous daughters - Kim, Khloe and Kourtney Kardashian and Kendall and Kylie Jenner - guests in attendance at Friday's (06.11.15) 'Great Gatsby'-themed party included Boy George, Will Smith and wife Jada Pinkett Smith, Melanie Griffith, Chrissy Teigen and John Legend, Tommy Hilfiger, Kyle Richards and Lisa Rinna.