There’s no doubt-- the 10-year marriage of No Doubt singer Gwen Stefani and her rock star husband, Gavin Rossdale, is not on the rocks.

Rossdale went for a hike with sons Zuma and Kingston and the family’s “hot” blonde nanny over the weekend, and some questioned a photo that showed the rocker’s placement of his hand on the small of the nanny’s back.

Check out the photo here.

But according to Radar Online, the joke’s on us. The site reveals that the pretty blonde who accompanied the boys on the hike is actually Rossdale’s 47-year-old sister, Soraya!

"All the speculation is hilarious," a source close to the couple told RadarOnline.com. "It really comes to something when a guy can't go for a hike with his little sister without being accused of cheating on his wife!"

Gavin and Gwen have dealt with rumors about their marriage before.

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