Why not? Girls dress to impress straight guys and since you're straight, you're best qualified to help us out... Some guys have great fashion senses and it doesn't make them gay. As long as you don't start acting all gay... then no one will think you are.
So give us advice! We're dying to know what you think.
Of course, why wouldn't they be able to? Whether you have fashion sense or not is independent of whether you are straight or gay. I'm straight and can give much better fashion advice than a gay friend of mine.