Today is National Siblings Day, and Marvel decided to celebrate this holiday by releasing a new TV spot for Guaridans of the Galaxy Vol. 2, featuring the inter-galactic sisters Gamora and Nebula, played by Zoe Saldana and Karen Gillan, respectively. This TV spot includes a hilarious scene where Nebula mistakenly calls her sister's group of superheroes the Gardens of the Galaxy, along with footage of Nebula trying to shoot down her sister in a spaceship. We also see Nebula trying to kill Gamora with a knife, prompting Rocket (Bradley Cooper) to proclaim that they have "issues."

This TV spot debuted on Marvel's Facebook page earlier today, and despite the obvious animosity between these two siblings, they will eventually be on the same side. A report from last January claimed that Nebula will be one of the new Guardians, along with Star-Lord's adoptive father Yondu (Michael Rooker) and the new character Mantis (Pom Klementieff). Yondu joins the Guardians after he is exiled from his group known as the Ravagers, since Yondu refused to punish Star-Lord for double-crossing them at the end of Guardians of the Galaxy. No specifics were given as to how Nebula and Mantis ultimately join the team, but it will be interesting to see if any footage will be released with Nebula fighting alongside her sister.

Oddly enough, this video comes just one day after Chris Pratt posted a new photo with Nebula, Yondu and Mantis all hanging out together in full costume, between takes on the set, although there weren't any details given about the scene that was being filmed that day. All of these characters are also returning, along with the primary Guardians themselves, in Avengers: Infinity War, which has been filming since late January, with production expected to last until this fall, since Avengers: Infinity War and Avengers 4 are being shot back-to-back. Still, it isn't known how the Guardians fit into that story, but Marvel president Kevin Feige has teased in the past that Guardians 2 does not directly tie into Avengers: Infinity War.

The MPAA confirmed last week that Guardians 2 will be rated PG-13, "for sequences of sci-fi action and violence, language, and brief suggestive content." The rating doesn't come as much of a surprise, since every Marvel Studios film has been rated PG-13, and Disney CEO Bob Iger said last year that the studio has no plans for an R-rated Marvel movie. Still, following the success of R-rated hits Deadpool and Logan, some are wondering if Marvel will eventually consider an R-rated movie. If they do go down that road, it won't happen until the studio moves into its Phase 4 lineup, if at all.

Then again, the studio doesn't necessarily need to take a risk on an R-rated movie, especially considering how successful its PG-13 movies have been. Guardians of the Galaxy Vol. 2 certainly looks to extended Marvel's streak of hits, with box office analysts predicting last month that Guardians of the Galaxy Vol. 2 may earn a whopping $160 million in its opening weekend, which also marks the first weekend of the summer movie season. It's certainly possible that it could fare even better, but that may depend on the critical reception and the buzz swirling around the film in the days leading up to its release. Take a look at the new TV spot for Guardians 2, which focuses on the sibling rivalry between Gamora and Nebula on National Siblings Day.

http://www.facebook.com/marvelstudios/videos/278041122623507/