“I think people need to know who I am and what I’m all about,” Mr. Tisei said. “I’m obviously proud to be married to Bernie, and I’m proud to be a Republican.”

For gay candidates, talking openly about a partner or loved one — let alone showcasing them in an ad — has traditionally proved tricky. And the Republican Party has been struggling to adjust to the growing acceptance of same-sex marriage.

But this cycle, three gay Republicans running for Congress — Mr. Tisei in Massachusetts, Carl DeMaio in California and Dan Innis in New Hampshire — are featuring their significant others in campaign ads, a first for a gay congressional candidate from either major political party.