[No-Man]

I prefer slow growth in my BE's. I like slow realization of what's going on, perhaps a bit of panic on the victim's part. I like it when they're doing something mundane before the transformation starts. Then there's a "huh... something weird is going on" moment before they realize their chest is getting bigger. Then panic, or at least confusion over what's going on. I don't really like it when the victim is super happy over the development (I made a pun!). Unless the victim deliberately BE'd themselves from the beginning, I would like some distress. I also like it when the transformation is pleasurable and increases the victim's libido so that their panic turns to lust as the transformation continues (or embarrassment over the lust they feel).

As for the sex question, yes I like sex. It's not necessary, but it can definitely make the scene more interesting, especially when the sex enhances the bust of the girl even more. I don't really like it if the sex is tacked on at the end. I like the sex to have something to do with the transformation itself.

These rules, of course, can be broken and I can still enjoy the BE's. It all depends on how the artist breaks the rules.