Mitt Romney went to the Chez Vachon restaurant in Manchester, N.H., on Monday to round up votes, but he ended up losing at least one.

Vietnam veteran Bob Garon, 63, was having breakfast with his husband when the former Massachusetts governor saw his veteran's hat and approached him to ask about his war service. But Garon was concerned about a different issue.

I have a question for you, he said to Romney. New Hampshire right now has some legislation kicking around about a repeal for same-sex marriage. And all I need is a yes or a no. Do you support the repeal?

Romney responded that yes, he supported repealing the law that legalized same-sex marriage in New Hampshire in 2010. I believe marriage is between a man and a woman, he said.

Amid the swarm of cameras and microphones that had surrounded the booth as soon as Romney approached Garon, looking for a photo op, Garon pressed Romney to elaborate.

OK, that means that if you're in the White House, you will not support any form of legislation that would change that so that servicemen would be entitled to benefits like a man and a woman? he asked. If two men get married, apparently, a veteran's spouse would not be entitled to any burial benefits or medical benefits or anything that the serviceman has devoted his time and effort to his country, and you just don't support equality in terms of same-sex marriage?

I believe marriage is a relationship between a man and a woman, Romney said again. The Defense of Marriage Act that exists in Washington today defines benefits, whether for veterans or nonveterans, as between married spouses, and for me, that's a man and a woman. And we apparently disagree on that.

It's good to know that you do not believe everyone is entitled to their constitutional rights, Garon said.

Well, no, Romney said. I think at the time the Constitution was written, it was pretty clear that marriage is between a man and a woman, and I don't believe the Supreme Court has changed that.

At that point, one of Romney's aides interrupted him to tell him he had to get to an interview with Fox News right now.

I guess the question was too hot, Garon quipped.

No, I gave you the answer, Romney said as he got up to leave. You said you had a yes or no [question]; I gave you the answer.

You did, and I appreciate your answer, Garon said. And you know, I also learned something, and New Hampshire is right. You have to look a man in the eye to get a good answer, and you know what, governor, good luck -- you'll need it.

That was one statement on which Garon and Romney could agree.

Afterward, Garon told reporters that Romney had lost any chance of getting his vote.

He doesn't even open the door to a conversation. It's just a boom, he said. I went and I fought for my country. I did my thing. I think my spouse should be entitled to the same entitlements [as] if I was married to a woman. What the hell is the difference? At least Obama will entertain the idea. This man is, 'no way, Jose.' Well, take your 'no way, Jose' back to Massachusetts.

You can't trust him, he added. I just saw it in his eyes.

Watch the exchange below: