Drunken night with my Sister

My sister Judith 26 is a quiet woman and doesn't date at all and since she finished university works as a researcher at the same university. She lives with me, I'm Martin 29 builder. I'm able to do just about anything plumbing, electrical and some carpentry. So I get work in renovations more than new builds. I like to play around and usually have a girlfriend or a fuck on the go. But I hadn't at the beginnings of December last year as the girl I was fucking got a new job on the other coast. I wasn't in a hurry and i didn't try too hard to find another girl to fuck. I'm average in build and looks, but usually done well with women. Judith is slim and has a great body and would be pretty if she wore makeup, but she doesn't try to impress men in anyway. She doesn't show much skin when dressed covered head to toe no makeup and wear glasses. Most male don't give her a second look. Our parents live in our old home town and we went to visit for Christmas. Staying several days, on our return I went out drinking with some buddies and got drunk. I got home just after midnight and started to undress and got down to my shorts and then fell asleep on my bed. Early in the morning I awoke to someone riding me and it was Judith, I was shocked at first. But decided to let her finish what she had started. On finishing I found she had put a condom on my cock after getting hard and then mounting me. I asked why did you fuck me and she said she was horny and playing with herself with a dildo didn't satisfy her anymore and seeing me out to it. Had decided to fuck me me instead, getting a condom out of my wallet. So I said anytime your horny just ask me. She was asking every second night for sex and after 2 weeks, she moved into my bed fulltime. Then I hooked up with woman Mandy 28 and bought her home, Judith was away for that weekend some science show. Anyway I really enjoyed fucking Mandy and I told Judith I had hooked up with Mandy and she said she was cool with that. Mandy moved in and 3 weeks later I was running late on a job and decided to work late to catch up. Getting home just after a 11pm, I found Judith in bed with Mandy and join them fucking both. Now we all sleep together every night, Judith and Mandy really like their woman on woman sex. I'm just the cream on top, which is a win win in my book.