I have always wanted to see my older sister naked but never figured out how until now. She gets up fairly early to go to work, and when she does it is still dark outside. One morning before her alarm went off I made sure I was up, snuck into her room and hid under her bed, far enough back to where she wouldn't see me but far enough forward so I could see her moving around. By the time she got up my eyes adjusted so I could see everything, and when the alarm went off she slowly got out of bed and went to the bathroom. She then came back and stripped off her night shirt, and I started getting hard when I found out she was naked under it. She then closed her door and turned on a small light on her dresser and I could see everything from her waist down. She has a few extra pounds on her, but still looked really nice from what I could see. I guess she was putting on some makeup and doing her hair because I could hear things moving around and she was shifting from foot to foot. A couple of minutes later she started walking around and getting clothes, and when she squatted down to get a shirt out of a drawer, her butt spread apart, I could see a little bit of her pussy lips and her large breasts hanging down. By this time I was hard as a rock and leaking precum all over myself.
When she got back up she started laying things out on her bed and her bare feet were right in front of my face. I couldn't see it but she put on her shirt, and then slid on a pair of work pants (no underwear!) and sandals. She grabbed a couple of things, turned off her light and went out the door. I didn't want to get out until she left because I didn't want her to hear me, but I had to cum. I started grinding against the carpet and in seconds I was shooting my load into my underwear. I had to lie in it for a couple minutes, but when I heard her leave I got up and took them off, right there in her room. My penis was covered in white and so were my underwear. I went to the bathroom and cleaned up, went back to my room and put on a different pair and went back to sleep. I haven't watched her again, but since then I have rubbed one out many, many times thinking about her naked body.