Girls definitely just want to have fun!

As X17 first reported back on July 12th, Lindsay Lohan and Lady Gaga enjoyed a slumber party together at the Chateau Marmont. Also partying with the ladies ... celebrity photographer Ellen Von Unwerth and songstress Lana Del Rey.

Too bad Lana didn't get cheeky for the cameras. Perhaps she was playing photographer, instead.

A source at Chateau Marmont told X17online exclusively:

    "[They were] watching old movies and playing board games [at the] slumber party. The three of them had dinner in the garden on Tuesday night at Chateau, and then Lindsay and Gaga ran upstairs to play dress up and came down in different outfits."

In addition to posting these photos on her website, Gaga Tweeted, "@lindsaylohan when you ordered a cucumber and a knife to the bar last night i thought your were gonna perform a vasectomy #justaskinnyb***h."

By the looks of their eyes in these candid snapshots, seems as though it was a pretty wild night. Rock on!