The American actor and the "Smile" hitmaker wed in Las Vegas in September 2020 and promptly set up house together in the U.K., but David worries his "goofiness" doesn't quite translate.
"I don't think they quite understand me there," he told the New York Post's Page Six. "I think in America I have a lot more leeway for someone of my goofiness."
"They have their own brand of goofy which is in its snark and wit. These are generalizations but, yeah it's not my brand. I think they find my brand a little boorish. That's alright, I'm not for all markets."
Speaking at New York's Tribeca Festival - where his latest movie, Steven Soderbergh's "No Sudden Move", debuted - Harbour also sang the praises of his bride and her two "amazing" young daughters.
"I'm in awe of her," he shared. "I think she's a remarkable, extraordinary woman and beautiful, talented, lovely, caring, but you know for some strange reason she also seems to think a lot about me, so it seems to work."
Of his new stepdaughters, Ethel, nine, and Marnie, eight, who Allen shares with ex-husband Sam Cooper, David added, "It's nice to be a part of their lives."
The duo began dating in 2019 and tied the knot with an Elvis impersonator officiating the ceremony.
About "No Sudden Move" itself, Harbour gushed, "It was a dream come true." He added, "It's got this real gangster, old school feel to it. I love the feel of this movie. I've never felt in quite such good hands."
"He [Soderbergh] isn't shooting any excess fat, he knows what to shoot, so our days would end…it would be three or four hours days, the way he shoots," he added. "I'm not used to it at all and yet I felt completely confident after it was done. I felt very taken care of."