Okay, we officially want to be BFFs with Cameron Diaz, Leslie Mann and Kate Upton.

Diaz and Mann appeared on Late Night with Seth Meyers Thursday, April 25, and hilariously admitted to drawing a mustache on their The Other Woman costar Kate Upton while she slept. They also dished about Mann's awkward—and allergic—kiss with the flick's hottie Nikolaj Coster-Waldau.

The actresses, who have become close friends since filming the comedy, revealed to Meyers that when 21-year-old model-actress Upton was asleep on a plane, they took full advantage of the pranking opportunity.

"She was fast asleep, like right away, which makes me so mad because I can never sleep on flights," Mann began. "So Cameron and I were up and we're like, 'Yeah, what can we do?' She's like passed out and we decided to draw [a mustache]."

Diaz laughed: "I'm drawing on her and she does not wake up … She's like a child! She's like a little baby."

Diaz, 41, and Mann, 42, went on to joke the bombshell would also hit the sack before them too. "Any time we go out, we're always like, 'Come on! Let's go!' And she's like, 'I'm going home. I'm tired.'"

Aside from bonding with her costars, Mann also enjoyed filming the flick because she got the opportunity to make out with male lead Nikolaj Coster-Waldau, best known as Jamie "Kingslayer" Lannister on Game Of Thrones

"I was so excited because I've been married [to Judd Apatow] for 17 years and I was like, 'Yes! I get to make out with the hot guy from Games of Thrones—this is awesome!'"

But the make out session wasn't as romantic as she'd hoped. "We kissed and I broke out in hives, like big hives on my face. So they washed him off because they thought maybe it was his after shave and we did the kiss again, and I broke out in hives again, and so, I'm allergic to him," Mann laughed.

The Other Woman is out in theaters now.