How do you add sexiness to a female novel character, but not cross that line of sluttiness.?

I agree with Junebug. If a male character describes her by saying she is the most elegant sexiest woman he's ever seen, she'll come across as sexy. If you make him say she's a B cup in a low cut dress, the reader sees it as she has her breasts on display and therefore she is slutty. It doesn't mean you can't describe her, but use the POV. Maybe the male character will like her breasts, but the way he describes them will change the entire impression. Saying "she had beautiful soft womanly curves" isn't the same as saying "she was a busty redhead."