We don't know why Harry Styles, Jennifer Lawrence and Adele suddenly seem to be a trio of besties, but we're loving every second of it.

Just days after the One Direction boy bander was spotted having dinner with Adele -- at the same restaurant as Jennifer Lawrence, no less -- they all partied with him at his 21st birthday bash in L.A. over the weekend. (We're assuming our invitation got lost in the mail.)

According to PEOPLE, other celebs that joined Harry on his milestone birthday included Chris Martin (who most likely attended with J. Law, obvs), Adele, Courteney Cox, David Beckham and Rashida Jones. While the mag reports that Harry's rumored new "gal pal" Nadine Leopold was in attendance, his rumored exes Kendall Jenner and Cara Delevingne also helped him celebrate. (No word on if Taylor Swift attended the festivities, but after this awkward encounter, we're going to go with "no.")

But the best part of the night didn't include the celeb guests or even the four cakes with his face on each of them (because that apparently happened). Instead, it's when he showed his true character and immediately called up the one person he most needed to celebrate with -- his mom.

"When he blew out his birthday candles, he FaceTimed his mom," a party source told PEOPLE. "He was so sweet to all his guests."

Harry Styles: Proving that he is better than every guy out there, one FaceTime to his mom at a time.

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