Actually, the odd thing is the sex in the Levitra ad is about the most wholesome adult relationship on TV. Nah, seriously... she looks like she's in love with her man, not just riding a sex machine... and a woman in love is very attractive. Just like the Diamond commercials ("I love this man, I love this man, I love this man...")
In diamond ads, it always seems to me that the woman is in love with the diamond. Maybe I'm being cynical.