We are non blood related and it's great
Well imagine as you will a single dad raising his teenage son in a small town. Well I was around 16 when my dad married let's call her Mary. Mary had a daughter about the same age as myself. I had met her before in school actually and we had that occasional damn you look hot looks during school. That was until we found out that our parents were dating. After that we ignored each other and except for when our parents started really getting close and eventually married we never even looked at each other.
Then Mary and um lets call her daughter Carie moved in. Carie and I slept on the second floor of the house with dad and Mary in the basement. Carie's room was directly across from mine. We shared a bathroom at the end of our short hallway.
Before the marriage we both had frequent masturbation habits but living so close we were forced to stop.
That was until one day Carie was supposed to be at track or something and I was at home in my room surfing the net for porn. I had just gotten started when I noticed the floor squeak behind me. I tried to cover up but I was completely naked and hard as a rock. As I craned my neck I saw Carie standing in the doorway with a shocked and embarrassed face. At first I couldn't talk I just sat there then she started to walk towards me. I mumbled what the fuck are you doing. That's when she asked if she could look with me. I was awestruck and said sure but if I'm naked your naked. In an instant she was sitting next to me rubbing her pussy. As we looked we told each other how often we used to masturbate. Then Carie without warning reached over and grabbed my throbbing cock and started to stroke it. Shocked I sat there for a second staring at her before I started to finger her tight virgin pussy. After a while we were both masturbating each other wildly wanting to please the other as much as possible until we both climaxed. Now we do this and more about once every two days.