I love my sister

And not in one of those innocent familial ways.  Every time I see her come out of the shower, I want to follow her into the bedroom, throw her on the bed, and make sweet fuck to her all night long.

Is this normal?  What should I do about it?

she doesn't wear pantyhose, and doesn't leave her dirty clothes in the bathroom.

i have snuck into her room when she's not home and put on her underwear.  but she's so much smaller than me, it ripped, so i stopped doing that so she wouldn't find out.

i masturbate in her bed if i think i can get away with it.