Andy Cohen Reacts to Sarah Michelle Gellar Calling 'RHOBH' 'Boring'

Andy Cohen isn't very happy about Sarah Michelle Gellar trashing "The Real Housewives of Beverly Hills" in his own studio ... and he's loudly calling it out!

The Bravo honcho reacted to SMG calling the ongoing season of 'RHOBH' "boring" during an interview at his Radio Andy studio at SiriusXM headquarters earlier this month ... and his issue is less focused on what the actress said, and more about her saying it in his own branded space! He aired out his feelings during his "Andy Cohen Live" radio show ... just listen to the clip.

He pleads ... "Don’t bring someone into my studio to trash my show. How about the door is locked when I leave? How’s that? Or maybe think twice about posting that all over social media where it says ‘Andy’ everywhere behind SMG." Point taken!

ICYMI ... Sarah was interviewed on "Page Six Radio" a few weeks back, and admitted she wasn't into Season 15 of the Bravo reality show, describing it as "slow." But, she noted, it was beginning to pick up.

And ... she (mostly) praised the cast, even saying she's down for a Jen Tilly and Kathy Hilton spinoff.