no this is not weird. its actually more common then people think.
Depends how hot she is ;)
No. Its perfectly normal to fantasize. Enjoy it!
No, you are wrong.
Men fantasize, yes, but when it's about your girlfriend's younger sister, then there is seriously something wrong in your relationship.
Yes.
You should discuss it with your aunt. If you can't do that then you have answered yourself.
If she looks good then go for it. Aunt's are the best
Yes it is and you know it or you wouldn't ask.
She has cancer
It's okay in West Virginia.
yes
Fantasize
Wrong? Not necessarily. Weird? Yes. Ask yourself, why does she like to sit on your lap?