I want to look sexy yet dress conservatively at the same time. Is it possible?

I really love your outfit! its soo cute already BUT what i would do to make it a little more sexy is change the opaque black pantyhose to lace black pantyhose like these ones.

http://www.blujay.com/1/525/3763430_s1_i2.jpg

Hope this helped!(:

Your outfit works, except that you can use a black or red dress as a substitute to the leather skirt. Make sure the skirt is about knee length for you, to maintain the conservative look.

The opaque black hose, how about sheer black pantyhose or stockings (stay ups or thigh highs and suspender belt) and of course instead of the leather boots, how about a pair of black high heels (pumps)

I like the direction you are going in, but a full turtleneck would unbalance it. I would suggest a mock turtleneck, or even a mock T-neck bodysuit. I agree with your decision to opt for the lace or patterned hosiery.

For boots, 3" heels are enough. If the heels are too tall, unless you find a pair that is absolutely stunning, they can easily begin to look gaudy. I really love the idea of the leather skirt, it's something I never would have thought of.

a simple black dress, a long sleeve one,and panty hose with the high heels

you can wear a loose blouse and a tight skirt with the shirt tucked in. HIGH HIGH heels!

I think yes, it is possible. It sounds like you're going to look extremely sexy at that party. I wish I were one of the guys at that party!