Kai Trump was living her L.A. girlie fantasy this weekend — rolling up to luxury L.A. grocery hotspot Erewhon with her Secret Service escorts in tow to grab some essentials … and the internet’s got a seriously sour taste about it!

Donald Trump’s granddaughter documented the trip in a video originally titled “I Brought My Secret Service to Erewhon,” later changing it to “I Tried the World’s Most Expensive Grocery Store” … showing her scooping up pricey items — including the famous $21 Hailey Bieber smoothie — plus supplements and other high-end goodies.

Kai seemed to be having a blast too … even checking out the store’s clothing merch and asking how much it cost — not that it looked like the price tags were slowing her down.

Still, she cracked a joke at the checkout about going bankrupt paying for it all … and the internet wasn’t amused. Critics quickly piled on, pointing out plenty of people can barely afford groceries right now — while others fumed that taxpayer dollars were footing the bill for the Secret Service detail.