We wonder what he was doing in Sin City?!

Ben Affleck returned to LA on a private jet yesterday after spending just one night in Las Vegas, and the actor must have needed to blow off some steam after his big week making headlines with new girlfriend Lindsay Shookus. This aircraft is owned by The Sands, and these planes are usually offered to people who spend upwards of $1 million at the tables, so we hope he wasn't gambling...

The actor has long been rumored to have a gambling problem, and it was allegedly one of the issues in his marriage to Jennifer Garner, but he's chalked it up to just being really good at blackjack in the past.

"I took some time to learn the game and became a decent blackjack player. And once I became decent, the casinos asked me not to play blackjack. I mean, the fact that being good at the game is against the rules at the casinos should tell you something about casinos," the A-lister told Details about being banned from the Hard Rock Casino in 2014.

"I had always liked blackjack. I don't play any other games of chance. I don't bet on football games, and I don't gamble at all, really, outside of that. But I knew with blackjack that there's a way you can improve your odds. And so I started trying to learn. And then I just got to a point in my life where I'm like, ‘If I'm going to do something, I'm going to try and do it really well.’ It was sort of presented like I did something illegal. You know what I mean?" he added.

He fessed up to the incident in order to clear up rumors he's a compulsive gambler.

"I get to correct the impression that there's something wrong with it or that it demonstrates some, like, compulsive activity. Usually, when you're a compulsive gambler, the casinos don't ask you to leave because you're beating them. You know?" he clarified.

He might not have a "problem," per se, but he certainly enjoys it.

The Batman star won 1st place in CA state poker championship in 2004, and he also used to partake in poker princess/Hollywood madame Molly Bloom's celebrity-packed secret tournaments in the early 2000s. The Boston hunk and other stars like Leonardo DiCaprio and Tobey Maguire would pay $50K a game to join, and it was the talk of the town.

Now that he's a free man, he can do whatever he wants! That is, until his new lady love starts imposing inevitable rules.

Meanwhile, Jen put on a brave face and took their three children to church in their Pacific Palisades neighborhood. We can't imagine what she's thinking!