Sydney Sweeney Has Tense Encounter With Ex-Jonathan Davino After Dinner in Los Angeles

9:52 AM PT -- A source who was near Sydney Sweeney's house when she got out of the car heard her scream ... "I don't believe you. Please leave, leave me alone."

Short story ... this seemed anything but a reconciliation.

Sydney Sweeney's night out in Los Angeles took a twist ... when she met up with her ex-fiancé right after dinner.

The "Euphoria" actress reunited with Jonathan Davino Saturday night just moments after leaving a private dinner with friends at celeb hotspot Giorgio Baldi in Santa Monica.

We're told Sydney and her pals dined in one of the restaurant's intimate back rooms, where they caught Game 7 of the World Series while sharing food and drinks.

Sydney looked stylish in blue short shorts, knee-high brown boots, a brown leather jacket, matching purse, and sunglasses.

After dinner, Sydney hopped into an Uber SUV, but her ride didn't last long. Just a few blocks away, we're told she was dropped off and seen getting into another vehicle ... this one driven by none other than her ex-Jonathan. The two then headed home together.

When paparazzi spotted her sliding into his ride, Sydney appeared to duck down, seemingly trying to avoid being photographed with him.