As long as there isn't any upside-down muffin top action going on, there's a lot of leeway in length. If a slender woman wears them all the way up to the curve of her butt, so that when she bends over I can see her cheeks pop out, she's still fine as long as we're not going to meet my mom/boss/etc.
But if she looks like she's in denial that her high school outfits no longer fit, I'm afraid I'll end up having to give her rides to the paycheck loan and pawn shop before I get her back to her trailer park for some double condom action. And that takes several drinks to even consider.
Think of spandex and go by this rule: you have to be built to size, it won't shrink you down to look like you are the right size.
I'd rather be with a curvy girl who wears shape flattering clothes, than with someone who thinks I'm attracted to meat crammed in a sausage wrapper.
I know a beautiful girl with wide hips. She tries several ways to complement them. I love it most when she wears the 40's ruffled skirts that taper up to her skinny waist, than when she slinks around in cat suit pants. Well, maybe I like her in those too... . I like it most when she dresses suggestively, more than confession-ally.
On the other end of the scale, if you're wearing surfer shorts, I tend to think you're more of the one-of-the-guys type tomboys. If I can tell you're attractive enough to warrant a makeover, and it might bring you out of your shell, I'd go for it. Most of the time dressing like a guy has the wedding ring effect: it makes you invisible to most single men.
The trick is to find shorts that fit your curves, that make a guy *wish* they were just a little bit shorter so he could see heaven... ones that require him to, and want to, work for it.