I'll quote a bud of mine when a girl said something very similar to this while we were all in a bar " Woman!, if you got the ass to move, it's a shame not to!" In other words, use your assets to the fullest, no guy can resist a fine booty, not many guys want a girl with no ass, in fact I can't think of a one. As far as the dancing thing goes, I'll let you in on this, 99% of girls look VERY similar when they dance. If a girl or guy is a great dancer you'll know, because they already do, and it shows in the confidence of their moves. It makes sense that you are more comfortable with your sisters, because ya'll probably are doing the same moves! Don't spazz so much about the dancing thing being the reason a guy will be interested. If he is, he already is, before he even got your name, or danced with you. Just concentrate on having a good time, not whether or not ya dance like a pro. If you are having fun, instead of standing around looking unsure and nervous, you'll draw attention, just by being yourself, as cheesy as that may sound, its the truth.