It all started Sunday ... Melissa – who has long struggled with weight issues – posted a photo of her slimmer self with friend and film director, Adam Shankman, as they attended the Centre Theatre Group Gala in L.A.

As you can see, Melissa looked terrific in her light green dress with a matching blazer alongside the stylish Shankman. She captioned the image with a combined message of going to the event with Shankman and getting closer to her dream of dancing onstage.

Enter Streisand ... Babs wrote in the comments section of Melissa's IG post, "Give him (Shankman) my regards did you take Ozempic?" Of course, everyone knows Ozempic is a controversial diabetes drug that can be used to lose weight.

While Barbra seemingly was not trying to be malicious, she received an avalanche of online criticism from Melissa's fans.

One supporter responded, "Wow really! What happened to not taking about Bodies!"

Another said, "I’m so totally taken aback that you could ask her that on Social Media for all to see?"

A third wrote, "Whether she did or did not is no one else’s business." And still others described Barbra's question as "rude," "nasty" and "disgusting."