Masturbation just came a natural thing.
At 16, I was at my boyfriend's house visiting. We were there alone as his parents were out for the evening. We were in the living room watching TV and just passing the evening. Soon, we started kissing each other and making out as we often did.
This time, we ended up laying down on the couch next to each other deeply kissing and hugging each other. As close as we were, I could feel his hard cock against my leg. It felt so good and exciting. I too was feeling the excitment of the moment as my pussy was getting all wet and aching for attention. This went on for awhile and he started grinding his crouch area against my thigh. It drove me crazy. I couldn't help myself and I reached down to his crouch and started feeling his hard on thru his pants. The reaction was immediate. His breathing got deep and fast and his kissing got harder as I rubbed his cock. Soon he too ran his hand down my shorts and started rubbing my slit thru my panties. We did this for a while and finally separated and removing our clothes from the hips down.
Here I was seeing a boy with a hard on for the first time and feeling it. It felt wonderful in my hand. Also my first time having a boy see and touch my hot wet pussy lips. He went back to rubbing my pussy lips and running his fingers inside as I helped guide him where it felt best. He too took my hand and showed me where and how to rub his cock. It didn't take long at all and he started making a grunting sound and started squirting his sperm juice all over my thighs. It was warm, white and gooey looking. I had no idea it would look like this. I also came to a wonderful orgasm soon after this especially after seeing him as he came. It was obvious he was in pure pleasure as was I when I came.
This was the start of a new part in our relationship with each other. After this event we lived to be alone and get it on with each other exploring each other's bodies followed by getting each other off. Everything was so great as it still is.