It’s no secret that Matthew McConaughey and Woody Harrelson could be half-brothers after McConaughey’s mother revealed she knew the Harrelson's father back in the day. This obviously raised a few eyebrows, and the former True Detective co-stars have been asked about the possibility ever since. Now, they're promoting a project called Brothers, and honestly, I never get tired of the two debating if that's really what they are.Thankfully, I don’t have to worry about the debate going away any time soon, as the big what-if is the subject of their upcoming series. The new show will have eight episodes and will be available with an Apple TV subscription. To promote the upcoming series, the two besties teased their actual brother debate with The Hollywood Reporter: Woody Harrelson: I’ve been wanting to, but he refuses.Matthew McConaughey: I’ll probably come around to it.Woody Harrelson: He might come around.Matthew McConaughey: If it’s true. I got a lot to unpack. If it’s not true, he’s not going to be near as fun to hang out with.Woody Harrelson: I’m going to be really sad for a while.In the past, McConaughey has notably been uninterested in finding out if this is true. He even turned down an offer from paternity “expert” Maury Povich to find out on his show. He has explained in old interviews that he doesn’t want to know if his father, who died years ago, isn’t really his father. And he's maintaining that opinion. As McConaughey's stated in the past, finding out that his "dad may not be [his] dad" could be why he has been so reticent about knowing for sure. As the Dallas Buyers Club star explains, “I got a little more skin in the game [than Harrelson].” However, this hasn’t stopped the two from being real-life besties. Their children even call each other uncle. Though you have to admit they really do look like brothers in the series’ promotional photos. Which leads to the bigger question: Will they reveal an answer in the series (when they don’t have one in real-life)? According to their conversation, we may not be finding out the truth in the series or in real life, as McConaughey is perfectly fine with keeping it up in the air: Matthew McConaughey: So, let’s just keeping floating this idea. Cause I like - I don’t want him being all upset.Woody Harrelson: I don’t think it’s going to be a problem, because I think it's - I think we’re brothers.Matthew McConaughey: He’s fully convinced. I’m not. There you go.I expect the fictionalized them will play similar roles in the series. Brothers follows two friends who discover they may be related after Matthew’s mother lets slip the possibility. Woody is the one who wants to dig into whether or not it’s true, while Matthew is concerned with a possible run for Texas governor. If you’ve seen the trailer, they’re definitely playing up the chaos the possibility causes in the best way. Plus, we already know the two actors have natural chemistry, so I predict that Brothers will be as heartfelt as it is chaotic. The series is finally hitting the 2026 TV schedule on September 23. I will definitely be checking it out, because the great debate of whether they're really brothers just never gets old.