'The Guardians of the Galaxy Holiday Special' makes a surprising revelation about Star-Lord's family

• "The Guardians of the Galaxy Holiday Special" sees Star-Lord feeling lonely over the festive period.
• Mantis and Drax try to find him a unique present to cheer him up at Christmas.

Although Peter Quill, aka Star-Lord (Chris Pratt), and the Guardians of the Galaxy recently showed up in "Thor: Love and Thunder," it's been a few years since a story in the Marvel Cinematic Universe centered around the rag-tag bunch of misfits.

Thankfully, director James Gunn has brought the gang back for "The Guardians of the Galaxy Holiday Special," which is a self-contained story and sees Star-Lord struggling with loneliness during the festive period.

But he's not the only one dealing with emotional issues over the holidays, as Mantis (Pom Klementieff) is trying to figure out how to tell Quill that she's actually his sister.

Yes, the alien empath is related to the plucky hero. That's the reason she's trying to kidnap Kevin Bacon (played by, you guessed it, Kevin Bacon) because she knows that the actor means a lot to Quill.

Obviously, Mantis is worried about how the news will affect Peter because their father, Ego (Kurt Russell), gave his mother cancer on purpose back in the 1970s.

Audiences will remember that Ego finds Star-Lord in "Guardians of the Galaxy Vol. 2" and explains that he's actually part Celestial. Ego fathered thousands of children across the universe in an attempt to take it over using plants that are part of himself.

The 2017 sequel also introduces Mantis for the first time, and she explains that Ego found her in her "larva state" as an orphan on her home world. Although fans have speculated for years whether the Celestial actually lied to her because he was her father.

Fans are given a concrete answer at the very beginning of the special, as Mantis is talking about her secret with Drax since he's the only one who knows the secret.

There was actually a deleted scene from the 2017 sequel in which Mantis talks to Drax about being related to Peter, although it was clearly removed so the plot point could be used further down the line.

Although Disney+ accidentally spoiled the reveal with a "Marvel Legends" episode about Mantis and Drax, it doesn't lessen the surprise.

While Star-Lord made an adopted family for himself with the likes of Gamora (Zoe Saldana), Drax, Rocket (Bradley Cooper), and Groot (Vin Diesel), it's nice to know he has an actual family member to lean on.

The Mantis revelation also means it's entirely possible that Peter and Mantis have other siblings somewhere in the cosmos. Sure, Ego killed many of his children in an attempt to spread himself across the galaxy, but who knows just how far his rampant reproduction went? (James Gunn, probably.)

"The Guardians of the Galaxy Holiday Special" is streaming now on Disney+.