​The brother and sister-in-law of former first lady Michelle Obama are suing a Milwaukee school that kicked out their children, with the couple alleging Tuesday that the dismissals were in retaliation for their complaints about racial bias.

Craig Robinson and his wife, Kelly, brought their action against the University School of Milwaukee on Monday after their two young sons were expelled last year.

“​As [with] a lot of the parents, we heard what was going on in the classroom because of COVID,” Craig Robinson ​told ABC’s “Good Morning America” Tuesday, “and there were repeated use of racial and ethnic stereotypes that were in actual assignments.

“The use of the word ‘plantation’ and things of that nature,” Robinson went on. “In addition to the racial and ethnic stereotypes, there was an insensitivity to socioeconomic status and as well as a disregard for the children who weren’t physically in the classroom​.”

The Robinsons enrolled their children, ages 11 and 9, at the school in 2016. The school expelled their older son in April 2021 and the younger one in June 2021.

Robinson said he and his wife approached the school about their concerns, but it “summarily dismissed our young children, retaliating against them because of the issues we brought up.”

“Just as recent as 10 years ago, the University School of Milwaukee had in their fourth-grade curriculum that students re-enacted the Underground Railroad, and students dressed up as slaves and ran through the school in the dark, and the teachers were actually the slave masters who captured these students,” Kelly Robinson told ABC.

“​O​ne of the other stories that we heard was about how the ​black students seem to get more harsh punishments than their white counterparts​,” she said. 

Craig Robinson said he and his wife are suing to hold the school accountable “not just to our two children who they retaliated against, but more importantly, there’s a whole community of people who are out there that we wouldn’t feel right if this happened moving forward​.​” 

H​e added that the school must change its behavior, “and this will help all students at the University School of Milwaukee.”

The school said in a letter to the parents that the children were expelled because the Robinsons had “not fulfilled the foregoing commitments as a partner to USM and its Middle School teachers and administrators.”

Steve Hancock, head of school at University School of Milwaukee, said the institution hadn’t been served with the complaint and did not have time to review it.

“We are not in [a] position to comment on this pending legal matter at this time,” Hancock said in a statement to “GMA.”

T​he Robinsons’ sons now attend a different school. ​

Craig Robinson is the executive director of the National Association of Basketball Coaches. He previously held the head coaching job at Brown University (2006-2008) and Oregon State University (2008-2014). He later worked for three years as the Knicks’ vice president of player and organizational development after spending one season in the same position with the Milwaukee Bucks.

Robinson left the Knicks in July 2020 to take the NABC post.