The 44-year-old — who began dating the Keeping Up With the Kardashians alum in 2011 — boasted about his fling with the 39-year-old singer during his Saint Pablo Tour in 2016.
West is said to have admitted during the tour to sleeping with groupies, before blurting out he hooked up with Milian.
“He was opening up about cheating on Kim and freaking out, and then he suddenly announced he hooked up with Christina Milian,” a source spilled to The Sun, adding: “He didn't go into detail about when and where it was, but mentioned Nick Cannon and bro code, as if he didn't really want him to know.”
Milian and Mariah Carey’s baby daddy briefly dated in early ‘00s. “It seemed it was all in the past, but he just wanted to spill his secrets, he was getting really manic,” the insider continued.
“His team were laughing and didn't really know what to say, in a way it wasn't too surprising, just Kanye being Kanye,” the source squealed, noting: “I don't know how Christina would feel though if she knew he was going around talking about bedding her, but at least he was complimentary.”
“Nobody knows if Kim is aware they hooked up, but it's clear they were close for years and worked together,” they concluded.
Ye and Milian toured together in 2004 and collaborated on the hit song “Diamonds” years later.
OK! reported, cheating rumors exploded after West released his controversial album Donda last month and the track “Hurricane” raised some eyebrows.
"Here I go actin’ too rich / Here I go with a new chick / And I know what the truth is / Still playin’ after two kids / It’s a lot to digest when your life always movin,” West raps in the song.
A source squealed, “the song is in a way his testimony of everything he did wrong and taking accountability for their marriage breakdown.”