Been messing around with my hot, and still hot, older sister for years, but now thinking about how it started. Things with her initially began out of anger. She had to take me for a dress shirt for some school function, and got mad that we couldn't find the right size quickly. Made some statement about working out and getting bigger (her bf at the time was a steroid-head). Something clicked in my brain to say, make her pay for that remark. I began going into her bedroom at night and feeling her body while she slept. Not happy with feeling her through her robe, I then learned to strip her naked (untie robe sash, slowly peel robe from her body..And I was VERY GOOD at it). Feeling and touching became fingering one night. Emboldened by getting away with it for months, including using a nail to unlock her door if she had it locked, I went for broke at 3am one weekend after she'd been out partying. Removing her robe and spreading her legs just enough, I mounted her and penetrated several times, to her heaving and deep-sigh reactions. When I was done and returned to bed, I wanted MORE.. So, going back in and getting on top of her again, I slammed her harder, waking her up. She was startled and shocked, digging her long nails into my arms, but, didn't scream or make much noise as I pulled out and stood up. "What the fuck are you doing?" she asked. "And put that thing away!". After a minute or so of fear and holy shit I'm in huge trouble, my hot, sex-loving sister told me to sit down. "I'm not going to say anything about this..Not that I shouldn't, since you were fucking me in my sleep, but I won't...Think you have the balls to fuck me awake?" she proposed, to my incredible surprise. "Yes" I answered, wondering if she meant it or was just leading me on to have someting to hold over my head. "Good. I'll let you know when. BUT, no more when I'm sleeping..Kinda freaked me out" she said, sending me to my own bedroom.