Kai Cenat Reggie

Kai Cenat's ripping into a former colleague who made unsubstantiated claims that Kai groomed a 17-year-old streamer ... blowing up at him in a profanity-laced tirade.

The streamer hopped online Wednesday and addressed accusations from his ex-pal Reggie, also known as Lil Rodney Son, that he groomed another member of the Clover Boyz, Rakai. Rakai denied the allegations against Kai as well.

Check out the clip ... Kai says he was going to handle all this drama offline -- and even planned on contacting authorities and his lawyers -- but he couldn't let Reggie continue to spread what Kai says are false allegations.