No one was home except my 16 year old sister, and she was busy doing whatever girls do.
At some point, usually while I was masturbating, my wife would open the door behind and watch.
After when we got more intimate , I would give her a clit orgasm and than an orgasm by penetration and right after she would masturbate her clit again while I was relaxing for another round.
Eventually we went out together for about 2-3 years.
One night her younger sister came downstairs quick , we were surprised as we did not hear her coming and my fingers were already massaging her clit.