Sherlock and Watson are never, ever getting together…at least on Sherlock.

During a Tumblr question and answer session, Sherlock co-creators Mark Gatiss and Steven Moffat addressed a bevy of fan questions about their series that stars Benedict Cumberbatch as Sherlock Holmes and Martin Freeman as Dr. John Watson. One of those fan questions tackled the topic of Sherlock and Watson's relationship: "Are you completely against the idea of Sherlock having a relationship with John? If so, what are your reasons?"

Gatiss fielded that question.

"Of course we're not against it. But as we have explained many times, that's not the story that we want to tell.

Obviously as a gay man myself, I have no problem with the notion that a Sherlock Holmes and a Doctor Watson could be in a relationship together, but ours aren't," Gatiss said. "It's as simple as that. Sherlock is clearly capable of feeling emotion and of falling for someone, but that someone is not John Watson, despite his love and great affection for him."

So, who is Sherlock saying, "I love you" to in the trailer?

"His mum, obviously. He doesn't ring home often enough and usually forgets her birthday," Gatiss teased.

"He's a very naughty boy."

This year Toby Jones will join the cast as Culverton Smith, the season's villain. "It's a brilliant performance. Funny and chilling. We can't wait for everyone to see it," Gatiss teased.

Season four of Sherlock kicks off on Sunday, Jan. 1, 2017. It's the first new batch of episodes—besides the standalone special January 2016 special—since 2014, and the only batch of new episodes until…? Could viewers get another standalone like Sherlock: The Abominable Bride?

"It depends on what we do next," Gatiss said. "Steven and I joked about doing a black and white episode set in the 40s where they fight the Nazis.

It's unlikely, but you never know."

Season five of Sherlock has been discussed, but when it will actually air is the big mystery.

"We all know how special this is. Shows like this hardly ever happen, and you could have a perfectly successful, happy career without anything on this scale," Moffat said when asked how Sherlock changed his life. "So we are grateful and a bit astonished. Can't say how it changed my life, except that it definitely made it better."