Paris Hilton Puts Son's Life Jacket on Backward, Social Media Concerned

Paris Hilton's parenting is under the microscope again ... 'cause people are pointing out another parenting mistake online after seeing a clip of her swimming with her son.

The reality TV star and mother-of-two shared a clip to TikTok where she hops in the water with her 1-year-old, Phoenix.

It's a sweet little video ... capturing loving mom Paris bouncing her baby in what looks like a lazy river on a relaxing day -- and, it seems safe. She's holding Phoenix tightly -- and he's happy and smiling -- so all good right?

Well, not quite ... 'cause according to a bunch of parents online, PH made a common mistake new moms and dads make -- she's got the life jacket on the wrong way.

Check it out ... little vests like the one Phoenix is wearing are supposed to have the big floaty in the front, holding on to the chest -- but, Paris put Phoenix's on so the floaty is on his back. Whoops!

This isn't your normal internet call-out BTW ... 'cause lots of the TikTokers genuinely just wanna help Paris, and they're correcting her kindly.

Many are admitting they made the same mistake or know people who have -- not a roast by any means.

Paris has been super open to these polite corrections in the past FWIW ... remember, just earlier this month fans let Paris know her kids' car seats faced the wrong way -- and, she not only made the change but thanked people for the tips!

Live and learn, we suppose ... it ain't easy being a new mom even if you are a celeb!!!

We've reached out to Paris' team ... so far, no word back.