OK! Or OMG?!: Gavin Rossdale And Gwen Stefani Split And Cheating May Have Been A Factor!

It's the end of an era! Gwen Stefani and hubby Gavin Rossdale have called it quits after 13 years of marriage and three children.

PHOTOS: Is Cheating Why Gwen Stefani And Gavin Rossdale Split?

What makes it even worse? Cheating may have been a factor. "Gavin always denied anything inappropriate,” a source tells RadarOnline, “but her friends warned her that it seemed like there was something going on.”

PHOTOS: Ben Affleck And Jennifer Garner Announce Their Split

Watch the video above for the inside scoop on the cheating rumors, and tell us your thoughts in the comments section below.