I am 30 and my younger sister is 25. She's really hot looking, completely fair with waist length long pitch black hair. Both of us are very possessive of each other. She got very angry when she came to know that I used to fuck my office receptionist and once even threatened to disclose it to our parents if I didn't stop it immediately. I was a virgin until two years ago but ever since I got involved with the receptionist in my office my sex life has literally exploded.
Anyways, both of us are not married and we really don't even know if we will ever marry for personal reasons. We are both in a physical relationship since past almost 2 years. We usually have sex late night after everyone's asleep. Our parents are quite old and were not bothered for either of our marriages.
My sister and I usually talk in the night after our parents go off to sleep. It all started when once she told me she wanted some one to fulfill her sexual urges and even I told her I too wanted a woman to have sex with frequently in the night after a hard day's work in office.
After a few weeks like that we realized she had "something" which I needed and I had "something" which she needed. So we finally decided to fuck each other to fulfill our appetite for sex. Now it's been almost 2 years since we started this. Our relationship is no more like a older brother-younger sister but that of a husband-wife. We often kiss and say "I love you" to each other just like husband-wife. Infront of everyone she calls me bhaiya but when we are alone she calls me by my name. Even while tying a Rakhi she winks and gives a naughty smile indicating that she wants a good fuck apart from the usual stuff. I must admit the sex is extremely pleasurable.
However once she asked me what will become of us after our parents and I was speechless. She told me after all this she doesn't want to marry anyone and wants to be with me only. Our relationship has become really physical as well as emotional. Even I think she is my wife rather than my younger sister. We both know what we have done and it's morally incorrect. I told her I do want to marry and want children of my own in the future and she said she also wants to marry and have children but she wants to marry only me.
On her insisting we once went to a gynecologist for my semen analysis and also her checkup and both my sperm and her eggs are healthy.
I know since we are direct siblings having kids using her egg and my sperm will be very risky because of genetic defects.
But I have read on the internet that children born of union between blood siblings do come perfectly normal if the parents are completely healthy and normal. In my case both me and my younger sister are perfectly healthy and normal with no history of defects.
Should we continue with it since both of us know we won't marry anyone in future or should we stop?