Here’s something you’d never catch on the TMZ Celebrity Tour … Rob Lowe getting mistaken for John Stamos on another company’s celeb bus ride — and let’s just say, he did NOT let it slide!

Rob dropped the awks moment on his IG this week — strolling up to the Hollywood Beverly Hills Tours bus and asking the passengers for a live identity correction after the guide boldly misidentified him as the “Full House” star … and while he tried to laugh it off, you can totally clock some low-key rage bubbling under that perfect smile!

While Rob and John are the same age and share that classic heartthrob aura, the passengers didn’t miss a beat, they knew exactly who he was — leaving the tour guide red-faced.

It’s still up for debate whether Rob’s genuinely annoyed or just letting it all slide with good humor — though he def seemed ready for Ashton Kutcher to jump out, asking in his caption if he’d been Punk’d.

This whole thing’s cringey as heck … and it begs the question, if the guide can confuse Rob with Stamos, who knows who else he might mix up. Zach Braff and Dax Shepard? Courteney Cox and Jared Leto? Heck, maybe “Love Is Blind” star Chelsea and Megan Fox?!?

Sure, some of these celebs do look alike, but if you’re leading those tours, you really gotta be on point with your A-listers, especially with those tourists shelling out their hard-earned cash for the Hollywood experience.