Actor Martin Freeman is set to wed his longtime girlfriend Amanda Abbington - on hit Tv show Sherlock.

The Brit's character Dr. Watson will surprise fans by walking down the aisle when the hugely popular detective series returns to U.K. screens for a third series next week (begs30Dec13).

The faithful sidekick to super sleuth Sherlock Holmes, played by Benedict Cumberbatch, will marry Mary Morstan, who will be played by Freeman's real life partner of 13 years, Abbington.

He says, "It wasn't a John (Lennon) and Yoko (Ono) thing, where I said, 'I want my missus (girlfriend) in'.

"I think they (casting directors) had thought about it and Amanda is a really good Mary. If she was nothing to do with me, she'd still be someone who'd definitely come up for it."

Abbington's casting in the show prompted a backlash from some fans earlier this year (13), with Internet trolls going as far as to issue death threats to the actress via

Freeman subsequently slammed the online abusers, saying, "To me, they're not fans of the show, they're fans of a show going on in their heads. Obviously I love Amanda and I want everyone to react positively to her; she plays a fantastic character and brings a hell of a lot to the third series."