I've watched it, and I can explain that the joke is he doesn't understand his wife when she's speaking Spanish. At one point, she objects to hunting and translates her remarks as being about something else altogether. So her assertion that he has "big ones" cannot be understood by him (at least not until he watches the ad with subtitles).
Is this a successful viral ad... even to appeal to Hispanic voters? For one thing, he's flaunting his inability to understand Spanish, even where he has the motivation to understand his own wife. It's a role-reversed "I Love Lucy" routine. And the wife, María Conchita Alonso, is Cuban-born. And that's the other thing. California may have a huge Hispanic population, 37.6% as of 2010, but the Cuban subset is only 0.2% of California's population. Isn't it a white perspective to see Hispanics as a single group? And isn't the Cuban subset most likely to be seen as different, given the political history of Cuban immigrants?
By the way, what proportion of Californians do you think are black? I was surprised to see — at that last link — that it is only 7.2%. There are more than 5 times as many Hispanic citizens as black citizens in California.
IN THE COMMENTS: Elise Ronan said:
FYI-Actually I think you misunderstood. He didn't say he married her, she said "he thinks he married me," when he mentioned that he married the sexiest woman in California.I rewound and watched that again and thought the joke was that she married him, not the other way around. Sorry I didn't get that, but that counts against the ad.
ADDED: I see that he is married, to a woman of Filipino descent. As a woman, I don't like him horsing around like that with another woman and, knowing that the woman in the ad is a professional performer, I am much more critical of her makeup. She needs a much fresher look for a political ad. I Googled her name and came up with: "Sean Penn gets into public fight with Maria Conchita Alonso at airport, calls her 'a pig' as she says he's a 'communist.'"