Leonardo DiCaprio and Gigi Hadid Grab Dinner with His Parents in London

Just when ya thought it was over, Leonardo DiCaprio and Gigi Hadid are still spending time together ... and even took their situationship to another level by hanging with his dad and stepmom!!

Here's the deal ... Leo and Gigi both ended their Tuesday nights at London's Chiltern Firehouse, but did their usual routine of arriving a few minutes apart.

She was with another model pal, and Leo was with his father George DiCaprio and stepmom Peggy Farrar. Coincidence? Maybe.

But, earlier in the evening -- after Leo took a stroll with his folks -- they'd ended up at yet another restaurant, China Tang, at about the same time. Fool us once ...

Sources with direct knowledge tell us ... Leo and Gigi attended a dinner party at China Tang, but it wasn't just them and his folks. We're told it was a 20-person event organized by Leo's pal British Vogue Editor Edward Enninful.

So, not a cozy, romantic, meet-the-parents type of deal, but they were all there -- and the night out comes after several months of Gigi and Leo "running into" each other several times in different cities around the world.

Just last month, the two were spotted leaving the same event at Cipriani SoHo in NYC ... just minutes apart. And, they pulled a similar move before that at a Met Gala after-party.

All of that has fueled dating rumors ever since they were first linked last September, but neither has confirmed anything.

We're guessing Leo's parents had a lot of the same questions -- for him and Gigi -- that you do.