Let's be honest...a girl could be wearing a plaid bra and striped panties, but if she's hot the guy is still gonna get turned on.
That being said, it is even hotter when the girl takes the time to coordinate the bra and panties. It looks better, and as was said below me, it shows that she put thought and effort into looking good for you. That's a huge turn on.
Its actually a huge turn on. Gives the feeling she actually gave that much thought to her lingerie as well as she gave to her outside self. Then its pretty much up to the guy to return the favor when she undresses ;-)
I think it is just plain sexier to see my girl in a matching bra and panty and a whole lot more aesthetically appealing. If she is also wearing a matching garter belt and stockings, oh baby, I see a multiple orgasm evening. For her and me.
I try to do it as often as possible, especially when I'm walking around the bedroom in front of my guy or when I'm seducing him because it feels sexier to match I think. But if I'm just getting ready for work or whatever, it really doesn't matter because I can care less what the girls that see me change think lol.
I feel a bit uncomfortable if I'm not wearing a matching set. But it's not always practical; for example if I'm wearing white pants and a black strappy top, I would have to match the lingerie to the clothes, rather than to each other. But generally I like to wear matching sets. I'm pretty sure my boyfriend likes it, but he's never complained when I don't.
Ok, honestly, I rarely wear panties. But when I do, yeah, I like them to match.
I never think about it! Also, I have tried to wear matching sets but it never works out because for some reason the companies that make those things think that if you have a big ass then you must be big on top too or vice versa... biggest problem