The collapse of Bennifer 2.0 has been devastating to fans, many of whom felt like they had the rug pulled out from under them. We mean, this was the two-decade love story, right? Ben Affleck and Jennifer Lopez were supposed to be endgame!

But someone close to the couple saw this possibility — and even warned Ben about it!

According to an insider spilling to DailyMail.com on Thursday, Matt Damon had some real words of caution for his old friend right when all this was getting started:

“Matt tried to warn Ben when he got back together with JLo that this could happen. Matt was there to help Ben get it together after their first split and he felt like this would happen again.”

Oof. We’ve all been there, right? When your friend jumps back in that toxic relationship because “it’s gonna be different this time”? Ben may not have heeded Matt’s warning then, but he’s looking to him now! The source says he’s particularly impressed with his pal’s 18-year marriage to Luciana Barroso — and knows the guy has some wisdom to share:

“Matt has had a successful marriage for years and Ben has always been in awe of this.”

Thankfully Matt isn’t the kind of guy to say “I told you so.” Instead, says the insider, he’s been a rock for his Good Will Hunting co-star to lean on amid the divorce drama:

“As things started falling apart, Matt told Ben that he supports whatever choice he makes but wants him to jump in and focus on his work.”

The old pals have worked on multiple movies together in the past couple years, including The Last Duel and Air. Their newest is something called RIP, a thriller just announced last week.

Ben Affleck and Matt Damon in 2006. (c) Timothy Jackson/WENN
It may seem like a distraction, but Matt is apparently serious. Apparently it was an area Ben wasn’t paying enough attention during his marriage:

“Ben spent so much time focusing on JLo’s projects just like he did the first time around. He told Ben, ‘What has she ever done for your career?’”

Damn. Brutal honesty. But that’s what the Justice League star needs! The source points out tough love is what’s going to keep the guy from falling off the wagon, something we’ve heard more than once is a big concern in tough times like this:

“Matt is the only real guy friend Ben has. He would not let him get back on the bottle and has been on him to make sure of this.”

We’re glad to hear Ben has someone in his corner rooting for his success — and showing him how it’s done.