Last week the oldest of Mitt Romney's five sons, Tagg, 42, raised eyebrows when he explained to a radio interviewer what it was like to watch President Obama assail his dad's truthfulness.

Tagg said the comments made him want to "jump out of my seat and … rush down to the debate stage and take a swing at him." He made the comments to North Carolina radio host Bill LuMaye.

"But you know you can't do that because, well, first, because there's a lot of Secret Service between you and him, but also because this is the nature of the process," Tagg said. "They're going to do everything they can do to try to make my dad into someone he's not. We signed up for it. We've gotta kinda sit there and take our punches and then send them right back the other way."

The comments raised eyebrows and were satirized on Saturday Night Live.

Sources tell ABC News that on stage after the debate last night, Tagg apologized to the president for the remark, a mea culpa the president quickly accepted.

A source close to the Romney campaign reports that Tagg's younger brother Josh, 37, notes that he has, in fact, taken punches from Tagg - and that the president has nothing to worry about.