When you hear the likes of Tina Fey and Amy Poehler, Keira Knightley and Sienna Miller or Beyoncé and Gwyneth Paltrow open up about their tight-knit relationships with a celeb pal, you can't help wonder if their friendships are real or for show.
After all, it's hard to decipher whether a celebrity's alleged BFF – one who would pose for snaps on Instagram and congratulate their success on Twitter – is the type of friend who is willing to share their last Tangtastic Coca Cola bottle and give an honest opinion when asked: 'Does my bum look too big in this?'.
However, in the case of Jennifer Lawrence, it sounds her relationship with actress Emma Stone is the perfect example of when industry friends can become best friends, IRL.
In an interview with Harper's Bazaar last year, J-Law opened up about the true extent of her friendship with Stone, recalling a moment when the 2017 Academy-Award winner cared for her after a late night of drinking.
'It was the night we saw Adele in L.A. She just started rubbing my back. She was really sweet. I was like, 'Get out of here. It's so gross',' she admitted.
Gross but cute, right?
Then came actress Michelle Williams who, during a screening of her Oscar-winning film, Manchester by the Sea last year, opened up about her other half – actress Busy Philipps – who has been her best friend since the pair filmed Dawson's Creek way back in the year 2000.
'I'm so in love with her. She's proof that the love of your life does not have to be a man! That's the love of my life right there,' she gushed.
In honour of our favorite celebrity friendships, we've rounded up Hollywood's best BFF relationships that prove you can be rich, famous and a badass mate:
1. Reese Witherspoon and Mindy Kaling
Everyone wants a work BFF they can recruit for mid-morning coffee runs, a quick gossip about a colleague on the way to lunch and someone who doesn't mind covering for you when you slip out from work 10 minutes early on a Friday afternoon.
And it looks like actresses Reese Witherspoon and Mindy Kaling have found their work/soul mates in each other, after recently filming Ava DuVernay's up-coming film, A Wrinkle in Time.
From holidays in New Zealand, Hawaii and catch-ups back in Hollywood, it seems these two just can't get enough of each other.
And, who can blame them? They're friggin' hilarious.
However, their friendship appears to predate their new film as, in 2014, Kaling created a Christmas tradition with the invention of a Wreath Witherspoon, which was later featured on The Mindy Project's Christmas Special and has since inspired Witherspoon fans across the world to make their own wreaths in honour of the actress.
In response, Witherspoon added a Kaling-inspired 'Wreath Witherspoon' dress to her clothing line, Draper James, so we have a feeling this friendship has been in fruition for a while now.
2. Kendall Jenner and Gigi Hadid
This pair's friendship is plastered all over the internet but, for us, its true strength was revealed when Gigi explained, on camera, how she and Kendall were related.
Yes, the pair are technically ex-stepsisters.
Plenty of BFFs over the years have pretended to be related but this pair actually traced four degrees of separation to forge a familial tie, before committing it to film.
3. Dakota Fanning and Kristen Stewart
The pair worked together on Twilight and The Runaways, and have talked before about how when they hang out, they don't talk about 'movie stuff', they just hang out like a coupla regular gals. The best moment, though, was when Dakota had Kristen's back post Kristen-cheating-on-Rob gate:
'I just think that media frenzies like that...Everyone thinks they have the right to, you know, publicize the struggles and sadness and heartbreak and all that,' Fanning told InStyle UK at the time.
'It's like, 'Why do you think you are the authority to judge people's experiences?''
4. Jennifer Aniston and Courtney Cox
The ultimate on-screen/off-screen friendship.
We watched these two in Friends and then we watched life mirror art, only sometimes worrying for Lisa.
The defining moment only arrived recently, though, when Jennifer made Courteney a bridesmaid in her wedding to Justin in 2015, a full eleven years after the hit US show ended.
Now, that's true love.
5. Katy Perry and Rihanna
In 2015, Katy felt Rihanna was snubbed by MTV for her lack of nomination for an MTV Video Music Award for BBHMM.
This, according to Katy, was a 'travesty' and she took to social media to tell everyone:
Some might question whether Katy should have got involved at all. Not us. We know best friends, and we know that Katy was just looking after Rihanna in the way any best friend should.
6. Cameron Diaz and Drew Barrymore
Recently Cameron proved she is just as close to Drew as she was in the Charlie's Angels days, revealing she supported Drew through her recent divorce.
It's clear Drew feels the same, tweeting out her praise for Cam's recent book launch.
All together now, 'awwww'.
7. Reese Witherspoon and Kate Winslet
These two met in 2007, and we knew they were the real deal when Reese had this to say about their relationship:
'Imagine my good fortune when Kate Winslet moved into my neighbourhood, rang my doorbell, and said, 'Dahling, Sam [Mendes] is off shooting and I believe our children are the same age. Could they possibly have a playdate, and, oh, by the way, it's almost nine o'clock and I've had nothing to drink - do you have any wine?''
If that's not the beginning of a beautiful friendship, we don't know what is.
8. Taylor Swift and Karlie Kloss
Leader of the notorious squad, Taylor appears to be best friends with the entire phone directory of A-list stars, including Selena Gomez, Lorde, Lenda Dunham and Ed Sheeran, to name but a few.
However, it's her friendship with supermodel Klossie which strikes us as particularly strong, possibly because they look so alike.
We knew they were made to last when they Instagrammed themselves drawing each other's names in the sand after a road trip across the US last year.
They're the closest living embodiment we have of the girlfriend twins emoji.