Kelly Osbourne Posts Cryptic Messages After Ex Sid Wilson's Slipknot Firing

Kelly Osbourne appears to be sending a pointed message ... just days after her ex-fiancé Sid Wilson was fired from Slipknot.

Kelly kicked off a string of cryptic Instagram Stories Monday with a blunt message ... "Wake the f*** up take some responsibility," before saying she was done putting up with the mystery subject's behavior.

"I want to be happy and I have a beautiful son to raise," she wrote. "Leave me alone. let me heal. I can’t protect you from yourself anymore."

She didn't stop there. In another Story, Kelly wrote ... "Also while I'm at it can I have my dogs back and all my possessions Oh yeah and maybe some child support?"

Kelly also reposted messages declaring she would protect her son "at all costs" and choose him over anyone or anything.

Another message took aim at "the loudest defense of the guilty," suggesting it is often a distraction rather than proof of innocence. Kelly added ... "This is why I always take accountability!"

Kelly never mentioned Sid by name or directly connected the posts to his firing, but the timing is certainly noteworthy.

As TMZ first reported, Slipknot permanently kicked Sid out Friday after more than 25 years with the heavy metal group.

Sources with direct knowledge told us the firing had been a long time coming, with the band finally reaching its limit over Sid's behavior and the way he allegedly treated his bandmates. We're told the band planned to announce Sid's departure this week.