My Brother David the black sheep of the family

I'm Michelle 27 and my only sibling David 31 and was a wild child growing up always in some type of trouble. He finished high school work for a time then joined the marines, my parents wee happy he was out of their hair for awhile. David done two hitches and returned back home, but got his own place. He was different, but also the same it seemed to me. I was working as a receptionist at the local doctors surgery. I wasn't smart enough to go to university, About 3 months after David's return our father got a promotion and a transfer interstate. They asked me if I want to with them, I had friends here and a job so I decided to stay, I was still living at home. There wasn't much in the way of rental housing in the town and no apartments at all, I couldn't afford to rent a house by myself. But our mother Helen asked David would I be able to stay with him in his 3bedroom house, as our parents were selling our old home to buy one in the new town. David just said if she wants there a spare room for her. So I moved in with David and his dog a large Bull Mastiff called Cuddles. Cuddles had a bedroom to himself as David let him stay inside at night. When David bought the house there was an old iron framed single bed left in the house, it needed a little fixing and David fixed and got a mattress and put a cover over the mattress. cuddles took it as his bed. David's military training meant he kept everything clean and in its place. I moved in with my own bed as the bedroom I was to use was empty except for built-in cupboard. My room was separated from David's room by Cuddle's room. Cuddles I had met before and he knew me which was a blessing as I moved in and David was away that day. Cuddles watched my every move, but was happy with me being there. David got home around 8 pm on that Saturday night and had a case of beer with him, I was still putting away my things. With cuddles watching me, Sunday morning awoke to my face being licked by Cuddles. I told him to go and he just looked at me, then David came in told get out and stay out and he left. I had breakfast David and he said Cuddles won't bother you again, I said he wasn't bothering me. I wasn't use to waking up getting my face licked. Best way ever wake up David replied with a big grin on his face. David was right Cuddles didn't wake again licking my face and stayed out of my room as well. A month later David had bought a car home he had bought and was going to do it up, he qualified as mechanic in the marines. He loved fixing up car and worked as a mechanic. I didn't owe a car and walked to work every day, once the car was fixed up and running David gave it to me. We went away to visit our parents it was Helen's 50th birthday and we returned home the next day. We were getting really well together and I walked in on him in the shower and he was masturbating himself. I was going to shower myself and only had on my bath robe and nothing else. David was a little shocked for a moment and I felt awkward seeing my brother cock in hand in the shower. David seeing my embarrassment, started to tease me. Saying there's plenty of room in the shower for 2, I was a bit annoyed by that as he was the one totally naked with his cock in his hand. So I decided to accept and embarrass him, I greed to join him in the shower and dropped my robe to the floor and joined him in the shower. It didn't faze him one little bit, he calmly handed me a wash cloth and told me to do his back and if I wanted I could finish masturbating him. I done as asked and started feeling a bit randy myself, one thing led to another and he fucked me in the shower. With us now having had sex, we kept up a sexual relationship in the 2 months since then and David third bedroom is again a spare bedroom as I'm in his bed every night. I've had boyfriend on and off, but it feels just right, me sleeping with him. David calls me his bedwarmer.