Matthew McConaughey and Woody Harrelson play off of THAT rumor they are real-life biological brothers in new trailer

Matthew McConaughey and Woody Harrelson have given fans a glimpse at their upcoming AppleTV+ comedy Brothers in the new official trailer. 

In the new series, McConaughey, 56, and Harrelson, 65, play fictitious versions of themselves who discover they might be brothers years after real-life rumors that they might actually be biological siblings.

The teaser sees Harrelson arrive unannounced at McConaughey's Austin, Texas ranch after his daughter's engagement dissolves.

McConaughey's mother Ma Mac (Holland Taylor) then reveals a longtime secret that the two friends might be brothers. 

Harrelson is determined to get to the truth of the matter, wreaking havoc on the ranch while McConaughey toys with running for Governor of Texas. 

In one scene, Harrelson's onscreen wife Brittany Ishibashi tells him, 'This is all very dramatic,' to which he quips, 'Of course I'm dramatic; I'm a f***ing thespian.'

There is also a zinger in which McConaughey haughtily describes himself as an Oscar winner before referring to Harrelson as an 'Oscar... what do you call it when you don't [win]?'

The cast is rounded out by Natalie Martinez, Ella Grace Helton, Noah Carganilla, Oona Yaffe, Nolan Almeida, and Highdee Kuan.

And the trailer sees a cameo from actor and Armchair Expert podcast host Dax Shepard.

The snippet was released across social media on Tuesday, with AppleTV writing in a caption: 'Based on a “true” rumor. Matthew McConaughey and Woody Harrelson star in the new comedy series, Brothers. Premiering September 23 on Apple TV.' 

The forthcoming show will stretch across eight half-hour episodes.

McConaughey teasingly fueled rumors that his bromance with Harrelson may be genetic last month, when he wished his longtime friend a happy birthday on Instagram.

Sharing a throwback photo of them together, he captioned, 'From another mother? Happy birthday, brother.'

AppleTV playfully commented on the post, 'Someone get these guys a comedy series.'

Rumors that the actors could be siblings started when McConaughey's mother Mary Kathlene 'Kay' McConaughey mentioned to Harrelson that she 'knew' his father, hinting at a past romance in West Texas, per Variety.

McConaughey was born in Uvalde, Texas, while Harrelson was born in Midland, Texas, divided by roughly 279 miles.

The best friends later pieced together that Harrelson's father, who was involved in dozens of murders in the 1960s and 1970s, had been on furlough around the time McConaughey's parents were getting their second divorce.

Harrelson's father was convicted contract killer Charles Voyde Harrelson, who received a life sentence for the 1979 murder of a judge.

During childhood, Harrelson had little contact with his father, who abandoned the family when he was seven.

As an adult, he tried to rebuild a relationship with Charles, visiting him in prison until he died in 2007.

Harrelson would like to know one way or the other, but the Dallas Buyers Club star has been hesitant to dig further as it would upend his understanding of his family history and the father who raised him.

Nevertheless, it inspired the duo to create their new show, which they also executive produced.