Britney Spears Goes Trampolining with Boyfriend Paul Soliz's Kids

Britney Spears isn't just back with on-and-off-again BF Paul Soliz ... she's also hanging with his kids again, and getting in some high-flying fun.

TMZ obtained video of Britney letting loose, jumping around Thursday at a Sky Zone in Thousand Oaks, CA -- with 3 of Paul's children in tow. While it seems likely Paul was also there, we don't see him in any of the video.

Britney’s obviously making the most of every bounce ... and even gave the zip-line a whirl before taking a plunge into a foam pit.

We're told despite Brit's trampoline triumphs, she and her crew only stayed for about 25 minutes before heading out.

This isn't the first time Britney's spent time with Paul's kids. She was photographed with one of his daughters back in September.

Thursday's outing makes it more clear Britney is back in the saddle with Paul -- the couple also recently hit up Nobu Malibu together, just weeks after she boldly declared she was "single as f***" on IG.

The two have had a rocky road in public -- we broke the story about their epic blow-up at the Chateau Marmont in May, which almost landed Britney in the hospital ... though she later brushed it off as just a foot injury .