Scarlett Johansson & Ryan Reynolds' Split: What Went Wrong?

Scarlett Johansson and Ryan Reynolds confirmed yesterday that they have decided to "end their marriage" and now fans are left wondering what went wrong? But with how private this star couple was, will we ever really know?

OK! NEWS: RYAN REYNOLDS & SCARLETT JOHANSSON CONFIRM DECISION TO "END THEIR MARRIAGE"

Scarlett and Ryan fans weren't the only ones surprised by their split — their own friends were too!

"No one had any idea this was coming," a friend of Scarlett's told PopEater. "They kept their private life so secret that I doubt we will ever really know what went wrong."

Only recently did the two begin opening up a little more to magazines about their marriage.

“Things change when you get married in general. But in terms of being a couple that’s in a public situation and speculated about and all that nonsense, it’s changed a little bit,” Ryan explained in the October issue of GQ. “I’m a little more guarded, I think. I’m a little bit more wary of having my relationship turning into a soap opera. I’ve just unilaterally not addressed it. That’s kind of been the fail-safe for me.”

And this "guarded" couple means fans shouldn't expect to read a tell-all about their split.

"In fact, knowing them, they will never talk about it at all," the source said.

OK! NEWS REPORT: RYAN REYNOLDS & SCARLETT JOHANSSON SPLIT

But Ryan will have to be out facing reporters to promote his upcoming film, Green Lantern, so some rules may have to be put in place.

"Anyone that asks personal questions will be asked to leave," the source revealed.

Ryan, 34, and Scarlett, 26, were married in September 2008.

On Tuesday the released a joint statement saying, "After long and careful consideration on both our parts, we've decided to end our marriage. We entered our relationship with love and it's with love and kindness we leave it. While privacy isn't expected, it's certainly appreciated."