... and promptly have a slumber party - yaaay! What do girls do at a slumber party? Well, they play dress up, discuss the fact that they don't have pillow fights, play board games, watch films, and chow down on popcorn, chocolate, maybe a pizza. Or just a cucumber.

Lindsay - a permanent fixture at Chateau Marmont hotel - was joined by the two singers and they apparently spent the evening together "watching old movies and playing board games."

A source told website X17: "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." We're not sure what Lana was doing at this point, possibly moping in the corner.

Lady Gaga tweeted Lindsay afterwards: "When you ordered a cucumber and a knife to the bar last night, I thought your were going to perform a vasectomy. #Justaskinnybitch."

Lohan tweeted back: "Skinny snack 1, Lady Gaga hahaha."

26-year-old GaGa then tweeted a photo of a tray with a cucumber with a knife in it and sliced lemons sitting on bar, with the message: "How much could one do with this arrangement!"

Her tweets and photograph have since been deleted, probably due to the backlash she received after tweeting the following comment last April: "Just killed back to back spin classes. Eating a salad dreaming of a cheeseburger. Pop singers don't eat. I was born this way."

As if pro-ana websites required further encouragement…

Someone needs to set up a finishing school for popstars under 30, 'cause they just don't seem to realise the impact their throwaway comments have on the impressionables. I nominate Grace Jones.