Well, it’s not like singer Gavin Rossdale didn’t have a somewhat secret past to begin with.  Two years into his marriage with singer Gwen Stefani, Gwen was hit with her first surprise – he had a daughter (now 22) with his ex-girlfriend songwriter/designer Pearl Lowe.  Surprising, sure.  But not xcompletely undealwithable (that’s a new word, now.)

The next surprise was a little more… well… surprising. 

Back in 2009, cross-dresser Peter Robinson (known as Marilyn) revealed that he had a brief fling with Rossdale back before he married Stefani.  A rumor?  Nope.  In 2010, Rossdale confirmed the relationship, saying that it was a one-time experimentation when he was 17 years old.  “That was it.  You have to onow what you like, and I know what I like,” Rossdale said in an interview with “Details” magazine. 

Oh, and then this:  Courtney Love claimed that she had an eight month affair with Rossdale while he was dating Stefani.  When it rains, it pours?

So now, Stefani is a little wary.  “Gwen often wonders what other secrets Gavin is hiding.  It’s getting harder and harder for her to go through the motions with a man she sometimes feels like she doesn’t even know,” a source tells “Star.”

Supposedly Rossdale, 46, and Stefani, 42, have been in and out of couples therapy trying to fix their marriage – but this “source” says that divorce is “inevitable.”  Bu maybe, just maybe, this source isn’t as connected as they claim.  A rep for the pair says that the rumors are “completely untrue – they are not divorcing!” 

We kinda lean that way, too.  Earlier this month, the pair was spotted out and about in Los Angeles with their kids at a park in Los Angeles – looking happy and worry-free.

Stay tuned, though….

Click Herefor photos of the couple.