First time caught

It was summer between freshman and sophmore year, my parents had left town to take brother and sister to camp. I stayed with my aunt while they were gone, as I had previous plans with summer job.

On that first Saturday, my aunt asked if I would help her work in the flower bed for a couple of hours, I didn't need to be anywhere until late in the afternoon,so I said sure. We went out back, me in shorts and t-shirt, her in long v-neck shirt that came almost to her knees. I had never thought of her as anything but my aunt, except now, I'm getting frequent glances at her pantied crotch. She's not georgeous, but tall, thin and fairly attractive with very small breasts. I know I shouldn't be looking, but can't stop. Her white cotton panties are sheer, and her hairy pussy is visible with some reddish brown hair sticking out. I stood up and moved hoping that my growing prick would go down, but no such luck, from standing, I could now peak down her v-neck and see her small tits with nipples sticking out like my little finger(about an inch and quarter). I knew that I was going to have jack off at lunch time, my prick was so hard and wet, it was difficult to keep it hidden. Finally, about 11:30, she said let's quit for the day. We put away the tools,and I made a bee line for the restroom inside the house.

Once inside, I locked the door, and dropped my shorts. I took a few tissues to clean some of the precum that had oozed thru the morning. I started to stroke slowly, now wanting to make it last, I edged as best I could,until I was reaching the point of no return. So, there I was standing in front of the sink, about to come when I hear the door open, and there's my aunt staring at my cock. I can't stop stroking, and my first pulse of cum lands right below her knee. I'm completely mortified, nothing is said(then) she takes a tissue, wipes her leg and walks away. I had never been seen jerking, none of my friends ever admitted doing it, and I had always kept it to myself. Though I was completely embarrassed, I was also strangely turned on by what had happened.

I got cleaned up, dressed went in the kitchen for lunch, my aunt said nothing, but had smile that maybe she liked what happened. I also knew, that I wanted to be seen again. 

Later, when I had returned from my few hours at work, it was just my aunt and I(her husband had died a few years earlier, and my cousin was spending the night at a friends)to eat dinner. We talked a little, and she asked if we could talk about what happened earlier, I must've blushed but said ok. Although she'd been married, had a child; she was pretty inexperienced about men,and had never seen a man masturbate. I wasn't full grown, but had a thick 7 inch cock.I told her about getting horny looking up/and down her dress, looking at her nipples and pubic hair. We both knew that sex was out of the question, but what did happen was we both got undressed and masturbated for each other with me cumming on her nipple. We continued to masturbate together many times later, which also included some oral.