Matt Damon says the green Speedo he wore in “The Talented Mr. Ripley” was always his favorite costume. But after shooting the HBO Liberace film “Behind the Candelabra,” a new item holds pride of place for the Cantabridgian: “I had a black and white bejeweled mankini.” Damon was in Pasadena, Calif., over the weekend to promote “Candelabra” at the Television Critics Association press tour. The film, which was directed by Steven Soderbergh and premieres on the pay cable network in May, chronicles the relationship between Liberace and his companion, Scott Thorson . Michael Douglas plays Liberace to Damon’s Thorson. “I probably spent more time in the wardrobe fittings on this thing than I had in the previous 15 projects, literally. Days and days and days,” said Damon. “And I really enjoyed it. Reading the book that the character that I play wrote, he really was taken with the glamour of this lifestyle. That was one thing that when writing the book, he talked about how impressed he was and how exciting it was to be involved in that kind of glamour.” Although many of the costumes are outlandish and there was an outsize element to Liberace’s personality, Damon says he and Douglas “weren’t giggling about it. We took it very seriously. These were people’s lives and we wanted to get it right and we wanted to get the script right. And we had the best director possible and we just worked really hard on it and were extremely happy to do it because we know how rare something like this is.” “Behind the Candelabra” costars Rob Lowe , Dan Aykroyd , and Debbie Reynolds . Damon joked that he would’ve taken his bejeweled mankini if he could have. “You’re not allowed to take those just in case there are reshoots, otherwise there’d already be paparazzi shots of me on the beach.” As far as Damon’s outfits go, we’re partial to the one he wore when he arrived at LAX on Thursday with his family. We love that Boston pride.