Burg, I didn't think the "dating younger women" part was mean. I thought that making that comment in the context of discussing viagra and other virility-enhancing products was mean. Maybe I'm just overly sensitive to the impotence issue-- or the "implied impotence" issue.
It seemed to me that what Mojo was saying is that "yeah, he has a hard time getting it up, but instead of taking any pills, he just dates younger women."
If the "dating younger women" comment had been in the context of other age-related issues (e.g., the taste of someone older vs. someone younger) like music or cars, then I wouldn't have thought it was mean. It was the proximity to his hypothetical sexual performance that bugged me AND the fact that she said this to another man, a stranger.
If they had been ALONE, I also would have not found it offensive, i.e. "You don't need any of those pills, babe, just keep dating younger women, and you'll be fine." [followed by a tongue kiss]