I only have sisters, so my answer is no. However, I did it with a male cousin. Young.
Well, I do not want to mention age.
At one point another girl cousin and I talked a boy cousin into playing ***** poker with us. To cut this tale down to compact size, we got to the point where he was in his boxers and we girls were in bras and panties and I also had on a t-shirt. Then I lost the t-shirt. Then he lost the next hand and should have dropped his boxers but he began to chicken out. Michelle (not her real name *grin*) threatened to tell his mother he had been playing ***** poker with us, so he agreed take off his boxers if we took off our bras. We did and he did and we were looking at him and I suppose we looked at all of him but I remember just staring at his erection. And then Michelle shocked me by asking him to ********** while we watched him (okay, so ********** was not the terminology she used) and he agreed to do it if we took off our panties and let him see us naked and we did and he *********** until his *** spurted out (I can stll bring that memory up of it flying out of his penis and arching through the dusty sunlight coming through the windows.
It wasn't as if we didn't know the Facts of Life -- our parents were modern and educated and enlightened -- and all that -- and there were lots of books with the right attitude that our parents read and did not hide away but left easily accessible to curious minds: books ranging from Our Bodies Our Selves to What's Happening to My Body (the girl version, of course) to The Joy of Sex. But we, of course, had wanted to see the real thing.
There were four of us girl cousins who would get together for sleepovers and tell secrets and talk about sex and boys and we would play ***** poker and then "secretly" pleasure ourselves in the dark. Except my cousin Michelle and I sometimes *********** together in the daytime. Not *********** each other, but both get naked an ********** at the same time. Which is what gave me the idea about the same boy cousin we had played ***** poker with.
So he and I got together and I brought up the topic of our ***** poker game and watching him **********. He was really embarrassed but I could also see a bulge in his pants that I knew enough to know that he was also sexually excited about the memory. There was a guy that I was interested in but I wanted to know more about guys before I got really involved. I didn't want to seem like a newbie, I wanted to be cool and sophisticated. I wanted to see the real thing, not pictures in a book. So we made a deal. We would both undress and ********** so the other could see. So we both undressed and it's a wonder our eyeballs didn't pop out of our heads we were both trying so hard to see all that there was to see and then he shocked me when he said I should go first. I bet I was beet red with embarrassment (and maybe some sexual arousal too) and began to play with myself with my right hand and was quickly moist and I took my good old reliable sexual best friend, my hair brush, into my left hand and inserted the handle into my vagina and played with my **** with the fingers on my right hand and he was staring at a me, eyes wide and mouth hanging open and his erection just pointing at the ceiling. I was beginning to be really getting in the groove and then I saw that he was touching himself and I was afraid (based on how quickly he had shot following our poker game) that he was going to ********* before I got to see all I wanted to see so (embarrassed to admit this) I faked an ****** so that I could be free to watch him **********. And then I asked "Can I touch it" and he said yes and I wrapped my fingers around it and tried to do the same kind of up and down stroking that he had been doing and he was panting and then suddenly liquid was squrting up from the tip of his penis, up in the air and coming down (mostly) on his naked body and I slowed my stroking then and just gently moved my hand on his erection as more liquid came out of that little hole in the tip and ran down onto my hand. After a minute or two I stood up and I think I asked him to come into the bathroom with me and clean up. I washed my hand and then too a wet washcloth and cleaned his *** off of his chest and stomach and thighs and rinsed the washcloth and used it to clean off his penis, which was now softer and only about halfway erect as I cleaned it, enjoying the look and the feel of it as I did so.
You see why I said that I had to try to "cut this tale down to compact size" -- I type fast (although not always accurately) and sometimes words just flow out of me and I can be so damned long-winded I could probably put everyone to sleep.
Sorry for that being one big lump of text -- I swear it had paragraph breaks when it was in this little input window, but when I clicked Save it came out all in one heap.