Do We Have This One?
"And I do not like your very big thighs, besides, you've been with too many guys."
- "Too Many Guys" by Group X
Big Beautiful Woman
meets Screw the Rules, I'm Beautiful!
More specifically, this is about female characters with an at least larger-than-average figure who are not only aware of their own attractiveness, but also take advantage of it, confidently and unapologetically. Other women might (or might not) tend to perceive their weight as an obstacle to seductiveness, but she won't bother to correct them; sometimes this might even be what she wants them to think.
For what it's worth, the only strong examples of this that come to mind for me now are within hentai, and even from what I've seen there, the concept isn't gone into much detail on. At the very least, the apparent popularity of this theme within hentai would seem to suggest that it's a popular enough concept to show up a fair bit elsewhere.