“No, I'm not engaged,” the 42-year-old comedian told The Washington Post, contrary to rumours.
The couple are expecting a baby at the end of the year, and it was thought that they would soon follow in the footsteps of Charlotte's brother Andrea, who recently married his long-term girlfriend Tatiana Santo Domingo.
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Charlotte, 27, who has been blossoming during her pregnancy – she is currently thought to be in her second trimester – has also been spotted wearing a dazzling engagement ring on her left hand.
Her dashing boyfriend Gad is currently on the other side of the Pond as he tries his hand at the US market, taking part in a three-day stand-up gig in French at legendary music hall The Birchmere.
He made his American stand-up debut in the Big Apple last week, where he isn't well known.
"Going to a comedy club where no one knows me — Americans sitting there and saying, 'Who is this guy?' — you’ve got to be funny," he said. “Comedy in America is very serious. Either they laugh or they don't."
Meanwhile, Charlotte is taking her pregnancy in her stride. She was pictured positively glowing as she shopped with a friend in St Tropez just days before her brother Andrea's wedding at the end of August.
She also took part in Tatiana's bohemian pre-wedding party, where she was beautiful in a white dress and gorgeous pink floral garland.
For the wedding itself the pregnant Monegasque royal chose a light blue transparent dress which highlighted her growing baby bump.