Kimberly Williams-Paisley laughed off rumors that her husband, Brad Paisley, is having an affair with Carrie Underwood Credit: Taylor Hill/Getty

Cheating on your partner is no laughing matter -- except, maybe, when it's not actually happening. Amid rumors that country superstar Brad Paisley has been having an affair, his wife of 10 years, Kimberly Williams-Paisley, stepped out in New York City and cheerfully dismissed the notion of his infidelity as ludicrous.

In fact, the rumors are so far-fetched that the Nashville actress, 42, wasn't even aware of them until Us Weekly caught up with her on Thursday, Nov. 21, at the 5th Annual African Children's Choir Gala.

"Am I in the National Enquirer?" she asked when Us brought up the gossip. "You're breaking it to me! What did I do?"

Once informed of the report, which claims that Williams-Paisley's husband has been hooking up with his CMAs cohost Carrie Underwood, the Father of the Bride alum (who, incidentally, played someone's mistress on Nashville last season) burst out laughing. "Are you serious?" she said. "Wow! I hope it helps our careers! That's all I can say." 

In reality, the couple's marriage is still very strong. "We have family Sundays together," Williams-Paisley told Us of life with her husband and their two kids, Huck, 6, and Jasper, 4. "We spend as much time as we can. We're very down-to-earth people. We come from good families, and we appreciate family." 

Asked what she loves most about the "I Can't Change the World" singer, she replied, "His sense of humor. [He makes me laugh] not all the time, but when it's important!"