Britney Spears, sister Jamie Lynn and all the kids take on Disney World -- and massive milkshakes

These desserts look so dangerously good, you might venture to say they're...toxic.

Britney Spears, sister Jamie Lynn Spears and all their kids headed to Walt Disney World this week and, of course, hit up Cinderella's Castle and Splash Mountain. But they had to duck away from the Magic Kingdom for a critical activity: Downing massive, out-of-this-world milkshakes!

The crew, headed by Britney, got the VIP treatment at the grand re-opening of Planet Hollywood at Disney Springs. Planet Hollywood posted footage of the family walking the red carpet to the screams of hundreds of fans.

In tow were sons Sean and Jayden James, Jamie Lynn's daughter Maddie -- who looks totally on the mend from her scary ATV accident last month -- and brother Bryan's daughter Lexie. Britney's mom Lynne also joined the fun.

The weather wasn't perfect, but the Spears clan still had a blast. Brit posted an Instagram album showcasing the entire day:

Britney has a longtime relationship with Planet Hollywood. In the early 2000s, she often made appearances at the Orlando location to promote album releases (and enjoy the food!). She's currently performing her Vegas residency at the Planet Hollywood Resort & Casino.

See photos of Britney Spears' sons: