Martin Freeman has admitted filming "Sherlock" with former partner Amanda Abbington wasn't "much fun".
The 47-year-old actor split from the actress after 16 years together in August and though he still thinks the 45-year-old star is a "fantastic actor", he found it tough shooting scenes as married couple John and Mary Watson quite difficult when they were in the midst of their problems.
He said: "She was and remains one of my favourite actors, I think she's a fantastic actor."
Asked how it was to work with her on "Sherlock", he said: "Awful! No, it was good, I really love working with her.
"By the time of the last "Sherlock" that we've done we were sort of in the midst of splitting up, so that wasn't that much fun, but when we weren't in that midst it was great."
The former couple have children Joe, 13, and Grace, 10, together, and the "Hobbit" star thinks they are managing to co-parent "pretty well".
He told "Desert Island Discs": "I always knew that people who split up can be civil and do it for the kids, it's all right.
"I didn't only want to be civil for the children, I wanted to be civil for us, because when you've loved someone for that long and they have been such an integral part of your life, what - that is supposed to not count now?
"That just didn't make sense to me so we do we get on well and I think the kids see us getting on well, they are just loved by the same two people in different geography now."
Martin praised the "rare" chemistry he shares with "Sherlock" co-star Benedict Cumberbatch but claimed some fans feel "betrayed" that they haven't taken their friendship further.
He said: "Probably nothing I've done, maybe nothing I ever will do, has resonated with certain parts of the world's population the same way "Sherlock" has, it just hit a lot of buttons for people.
"The reaction can be quite intense. So by the time we filmed the last ones there were some fans who were so adamant that John and Sherlock were gay, they knew it and they knew that Steven (Moffat) and Mark (Gatiss) were going to write an episode where we held hands off into the sunset together, and so when that didn't happen there was a chunk pf people going, "This is betrayal".
"Put it this way, they invest a lot in it and up to a certain point, that is delightful. Beyond a certain point, it's more challenging."