Not exactly EUF, but it has elements of it. It starts with a woman coming out of changing room at a beach/pier. She doesn't want to be seen in her bikini though, so she carries an inflatable raft to cover herself (at least from the camera). Towards the end of the ad, the raft is losing air. Once it completely deflates, it drops, revealing that she's wearing an itsy-bitsy, teenie-weenie, yellow polka-dot bikini like the one in the song, which is also playing during the ad. Then the woman realizes that she doesn't need to cover her body since she looks good, due to eating Yoplait Yogurt of course.
Kinda disappointing that she's only wearing a bikini and not underwear (which would be a lot hotter in my opinion), as well as the fact that she's not embarrassed by the end. But I do like that for a majority of it, she's embarrassed to be seen in the bikini and is trying desperately to cover herself. The ad can be seen here
http://youtu.be/ul_ZSOOUENI