Los Angeles, Oct 31 (IANS): Rapper Tyga is reportedly not happy with his former lover and model Blac Chyna after she appeared to diss him while calling their son King Cairo "ugly" in a video she posted on social media.

Only days before she gives birth to her second child, her first with fiance Rob Kardashian, Chyna shared a video on Instagram over the weekend, in which she bared her baby bump as she busted out some moves to the hit single "Juju on that beat". 

She also lip-synced the lyrics and approached her son, who seemed uninterested in his mother's dance, when she mouthed the line: "You ugly, you yo daddy's son." 

However, Tyga didn't seem to find the joke funny. 

"Tyga is not cool with Chyna calling King ugly, joking or not. He thinks Chyna's a really good mother, but made a big mistake with saying what she did and then an even bigger mistake by posting on social," a source told hollywoodlife.com.

"That's just way out-of-pocket and King is a highly intelligent kid who remembers everything and Tyga's certain he'll remember this," the source added.