Actress Kristen Bell has blasted a veterinary technician for making up false allegations she and her fiance Dax Shepard recently had sex at an animal hospital.

Earlier this week (begs11Feb13) bosses at Star magazine published a story suggesting the pregnant star and Shepard made love at the Laurel Pet Hospital in West Hollywood, California, while their dog, Shakey, was being examined.

A source told the tabloid, "Another employee walked in on them, and they was basically on the exam table. Kristen apologized and explained her pregnancy hormones just made Dax irresistible - even in the vet's office."

But now the furious mom-to-be has taken to her WhoSay account to shut down the report, writing in a series of posts, "Haha this is gross. Obvi (obviously) this never happened and if I ever WAS turned on around the smell of dog p**s I certainly wouldn't apologize for it...

"Thanks to whichever dude at the Laurel Pet hospital had the integrity to make up and sell a story. You are a real piece of s**t. See you never again!"