New court documents filed by Tameka Raymond reveal she thinks the singer is using Kyle's death to get sympathy from the media and his fans.
The 11-year-old died on July 22 two weeks after sustaining horrific injuries in a boating accident.
Tameka's allegations come after Usher requested the former couple's upcoming custody hearing be delayed due to the tragedy.
In the court request, Usher claimed he was concerned the hearing would cause both parties "unnecessary stress and strain … in the immediate wake of this tragedy."
But according to court docs obtained by TMZ, Tameka reckons his claims are "bogus".
Usher "visited Kyle in the hospital only once" during the 11-year-old's 15 days on life support, wrote her lawyers.
Tameka has asked the judge to deny Usher's request, saying it's just a "transparent sham".
The singer failed to attend Kyle's funeral.
Usher and Tameka divorced in 2009 after only two years of marriage. They have two children together, Usher Raymond V and Naviyd Ely Raymond, while Kyle was a son from one of Tameka's previous relationships.
Both parties are seeking sole custody of their sons. Usher has accused Tameka of being unstable, while she claims his cheating (he allegedly slept with her bridesmaid) caused her depression.
The next hearing in their bitter dispute is August 13 unless Usher's request for a delay is successful.