Amber Rose & Danielle Bregoli Somehow Ended up in a Hot Tub Together

Amber Rose was kidding when she said Danielle Bregoli was her daughter ... but she left no doubt she's a Bregoli fan.

Amber and Danielle -- aka Bhad Bhabie -- each posted this video on their Instagram story over the weekend ... chilling in a hot tub and leaving many to wonder what the hell they were doing hanging out. It's an unlikely friendship ... we're not aware of any mutual friends. But, unlikely friendships seem to be Danielle's thing.

TMZ broke the story ... Danielle and David Spade turned an early shade fest into a surprising collaboration when he ended up in her "Gucci Flip Flops" music video.