Claire and Hugh starred as married couple Sue and Pete Brockman for seven years on the hit BBC comedy, revealing that they were an item last year.
During an interview on Thursday’s episode of Lorraine, Claire touched briefly on the relationship, admitting it’s not something she had seen coming.
“We are together,” she told presenter Lorraine Kelly. “It’s a lovely little life surprise. It’s a lovely thing.”
Hugh confirmed the relationship last year, after rumours began circulating that he and Claire were an item.
Speaking outside his home, he told reporters in July 2018: “I am very, very happy, we are so very happy… It’s nice and yes, it’s so lovely.”
The couple last appeared on screen together in 2016, when they reprised their Outnumbered roles for a Christmas special. They are not thought to have started dating until production on the show had ended.
Before her relationship with Hugh had been made public, it was thought that Claire was still with ex-husband Charles Palmer, but they had actually split up two-and-a-half years prior.
Claire had kept the break-up private by continuing to refer to Charles as “my husband” in interviews.
In Outnumbered, Claire and Hugh played parents to three children, played by child stars Tyger Drew-Honey, Daniel Roche and Ramona Marquez, who viewers watched grow over the course of the series.
Lorraine airs every weekday from 8.30am on ITV.