Tyga's former fiancée wants primary physical custody of their two-year-old son, King Cairo.
The 25-year-old rapper, who is dating 17-year-old reality TV star Kylie Jenner, is allegedly on the cusp of a bitter court battle with Blac Chyna, as she is unhappy about his relationship with the 'Keeping Up with the Kardashians' beauty.
Sources claim the 27-year-old model, who split from the 'Ayo' hitmaker last August after three years of dating, hired a top lawyer last week because she thinks their child needs to have a more consistent home environment before he starts pre-school later this year.
An insider also told gossip website TMZ.com that the entrepreneur - whose real name is Angela Renée White - is deeply upset that Tyga is dating a minor and thinks it shows bad judgement that could affect his parenting abilities.
She doesn't want their son spending substantial time with Kylie because she believes she lacks maturity, but is willing to give him weekend visitation rights.
Shortly after the former couple ended their engagement, Tyga - whose real name is Michael Ray Nguyen-Stevenson - was said to be planning to seek full custody, but then agreed to share joint custody.
Blac recently insisted she had no "beef" with Tyga.
Asked about how he could get back on her good side, she said: "I ain't got beef with him. He's already on my good side."