Not everyone is buying that Tristan Thompson is a changed man. After Kim Kardashian praised the NBA player as a “good dad” on the most recent episode of The Kardashians, he and the reality star were slammed by the aunt of his first son, Prince.

On the hit Hulu show, Kim referred to Tristan as a “good friend” and a “good dad” to his two children with Khloé Kardashian: True, 5, and Tatum, 1. She even revealed how he has stepped up to the plate and helped her amid her divorce with Kanye West.

“When he saw me struggling with my kids, he stepped up,” she said in her confessional. “He started showing up to the games. He picks Saint up, takes him to dinner. And will always come to my defense — especially if it’s stuff with me and my ex.”

After the episode aired, Tristan — who shares 6-year-old son Prince with Jordan Craig — received a scathing message from her sister, Kai, on social media.

“It’s so painful to see how Tristan can find the time to do these nice things for others but can’t seem to show up and be a real parent for my nephew Prince,” she wrote on Instagram. “The fact that he can take other children to school and activities in the same city, yet never sees or speaks to his own son, unless it’s for a party or planned photo opportunity, is appalling and inexcusable.”

Kai then took aim at Kim for not considering Tristan’s other kids when she spoke highly of his parenting skills.

“I don’t want to believe that you are this insensitive to the fact that he literally ignores his children,” she continued. “That’s nice if he’s been a good friend to you, but let’s consider our sisters before taking to global platforms to defend this man’s character.”

According to Kai, the athlete — who also fathered almost two-year-old son Theo with Maralee Nichols — has “not paid” child support to Jordan in a “very long time” and has allegedly stopped paying Prince’s school tuition. She even claimed he hasn’t asked about where his son is going to school now.

“Yet he’s being applauded for picking up/dropping off other kids to school/activities,” she wrote. “Despite it all, my sister continues to work multiple jobs as she has since she was 16 years old, so that Prince will never have to feel a difference. But regardless, stepping up for your son is not all about money, it’s about the time spent.”

She added, “@RealTristan13 you are NOT a good father if you can’t be a good father to ALL of your children.”

Decider has reached out to reps for Tristan and Kim, but did not hear back by the time of publication.