Matthew McConaughey's mom's comment led to realisation he and Woody Harrelson may be brothers

There are times when family secrets kind of slip out. At least that's how it appeared when Woody Harrelson revealed a conversation with Matthew McConaughey's mom made him think they were brothers.

Now, there are worse revelations a man could have.

I mean, the two actors have a fully fledged bromance and it's such a cute thing to watch.

But even though they only thought of it as a friendship, it could be a lot more than that.

In fact, it might be deeper than skin deep.

McConaughey previously said in an interview that his mom let slip a little detail which was instantly picked up by the two men.

Could the pair be brothers? (Instagram/@officiallymcconaughey)

He explained: "In Greece a few years ago, we’re sitting around talking about how close we are and our families. And my mom is there, and she says, ‘Woody, I knew your dad.’ Everyone was aware of the ellipses that my mom left after ‘knew’. It was a loaded K-N-E-W."

So, this led to Harrelson to really believe that they could be connected by blood.

I mean, come on. Look at their faces and they way they talk. If they're not related, then what the hell?

We're going to need Maury Povich to convince them to take a DNA test and pronto.

Anyway, when asked about the story while doing the media rounds for his new series White House Plumbers, Harrelson said there could be some truth to it.

"Well, I’ll just say there is some veracity to that thought because we talked to Ma’ Mac, Matthew’s legitimate mother, and she let us know one time… I mean, this is crazy," the 63-year-old said, retelling the same story McConaughey did.

McConaughey's mom said she 'knew' Harrelson's dad. (L. Cohen/WireImage)

"We were in Greece watching the US team win the World Cup and I don’t know, I mentioned something about regrets.

"And I said, 'You know, it’s odd that my father has no regrets'.

"And I have known Ma’ Mac a long time, and she goes, 'I knew… your father'. And it was the ellipses I found a little troubling, or interesting. 'I knew your father'."

If this still doesn't make you think it's true, here's what he said next and it's wild.

Harrelson continued: "The year of [McConaughey's] birth, nine months before, she was on a sabbatical from her relationship with his supposed father, Jim."

Doing a little digging into the past himself, McConaughey, 54, said: "We went on to unpack what this ‘knew’ meant and did some math and found out that [Harrelson's] dad was on furlough at the same time that my mom and dad were in their second divorce.

Harrelson says he's keen to do a DNA test. (Instagram/@woodyharrelson)

"Then there’s possible receipts and places out in West Texas where there might have been a gathering, or a meeting, or a ‘knew’ moment."

All of this led to Harrelson suggesting the pair get a DNA test to see if they really are related. I mean, you would want to know, wouldn't you?

Well, not everyone; McConaughey was a little more reluctant about the whole thing.

"Look, it’s a little easier for Woody to say, ‘Come on, let’s do [DNA tests],’ because what’s the skin in it for him?” he said.

"It’s a little harder for me because he’s asking me to take a chance to go, 'Wait a minute, you’re trying to tell me my dad may not be my dad after 53 years of believing that?' I got a little more skin in the game."