I had been going out with Ashley for two weeks when my 18th birthday came around this past June. We had kissed a lot before then, but Ashley was very reluctant to do anything more. I tried to work my way into her pants and shirt but she kept refusing. Turns out she wanted to keep clean until she gave me my birthday present.
My birthday was a Saturday so I had the entire day to celebrate without worrying about school. Ashley came over at noon so that we could hang out before I had my party in the evening. We were just hanging out in the TV room talking and watching some movies with my younger sister Meg who is 16. At the end of one of the movies (at about 3 pm) Meg got up to go to the bathroom and I took the opportunity to get a little frisky with Ashley. I started to kiss her and caress her butt like I love doing. Then I heard Meg coming back so I stopped but by then I had a nice boner going.
We got back to watching a different movie and a minute or two in Ashley took the blanket on the couch and threw it over our laps. I knew what was coming next. She slowly moved her hand toward me under the blanket, first reaching my knee and then working her way up the inside of my thigh until she hit the head of my now very very hard boner. She gave it a rub and then continued down the shaft, and as she did that I felt some precum leak out of my dick and into my boxers. As she continue to rub my dick and then balls, more precum started flowing then ever before with exception of my first handjob when I was 14. I could feel my boxers getting wet and was in heaven when Ashley unzipped my jeans and pulled out my dick. As soon as she did that I felt like I could cum but I didn't. She gave me a stroke and the precum made that slurpy sound it makes and we froze, realizing that my sister probably just heard that. Sure enough Meg looked straight at us and asked 'What was that?'
'What was what?' Ashley responded. I personally was paralyzed and couldn't respond.
'I think you know what I mean,' my sister said back. But then she dropped it and went back to watching TV and Ashley went back to stroking me as quietly as possible. She was pretty quiet until about two minutes after the first slurp a second one happened.
'Are you guys really doing that?' my sister asked, obviously on to us. I was horrified but my girlfriend didn't seem to mind. She said 'Yeah he's covered so it's no biggie.'
'Yeah I saw it once...it really isn't,' my sister said, in reference to one time she saw my dick accidently and noted that she expected it to be bigger.
I said 'fuck you' and then Ashley said 'well if you've seen it there's no need to ruin your blanket!' and stripped the blanket off, exposing my dick to both her and my sister, which turned me on a lot despite a split second of panic. Before my sister could even finish saying 'ewwww' I felt the cum rising and after another two strokes I started exploding. My cum got all over Ashley, my shirt, my shorts, my boxers, and my legs but luckily not on the blanket. Ashely got up to get some tissues and Meg and I just sat there looking at each other. I looked at her odd facial expression as she looked at my dripping still hard dick. It must have been quite a sight. Ashley came back with tissues and started cleaning me up.
I was still so horny that I begged Ashley to give me another handjob. She did and Meg accidently walked in on us, not that we were trying to avoid the audience, she just didn't know we would still be doing stuff.
After we were done, I felt bad that Ashley put Meg in that position so the next day I talked to my sister. She said it was okay and that she actually liked seeing my dick (she blushed as she said that) but that it was weird for her.
I guess Meg warmed up to seeing Ash jack me off though because she stayed for another one of our shows later that month. I came pretty hard that time too.