It's one of the biggest sexual taboos, and one that's outlawed around the world.

Incest - sexual relations between two closely related people - is frowned upon, but those who've actually done it have shared their incredibly revealing accounts.

One woman said she ended up fathering two children with her brother and they all live happily, while others say they've been mentally scarred by their forbidden encounters.

The stories emerged from an AskReddit thread, generating anonymous accounts which were in turn revealing, shocking, and at times heartbreaking.

One woman revealed how she'd slept with her brother after they'd been "bounced around foster homes a lot".

They ended up with an "incredibly religious and overprotective" couple who homeschooled them and rarely let them leave the house.

"Both he and I went for months without any sexual release and barely any contact with the opposite sex outside of each other," she wrote, recalling when she was 15 and her brother was 14.

They decided to meet in the bathroom one evening, in an encounter which she says was complicated.

"Although it was consensual, at the time I kind of felt that I forced him into having sex with me. He was hesitant, since he didn't want me to regret it in the future, but I insisted. So, he accepted.

"It was probably my biggest regret for most of my life after that and I feared that he had deep seated resentment for me. He's pretty much the only family I had left, and I was afraid that I would lose him too due to my selfishness.

"It took over 10 years for me to finally go to him and ask for forgiveness, and to my surprise he wasn't mad at all. It was a huge relief, and he and I aren't awkward around each other anymore."

One man said he had sex with his sister when he was 17 and she was 14, and immediately felt scared, ashamed and confused.

Afterwards he said: "I ran to my bedroom and covered myself under the blankets with a huge shame feeling. I spend the whole night wondering if I raped her or if she actually wanted it.

"The next day she acted normal, but I couldn't look her in the eyes.

"I felt shame for years, even though I really got the feeling she also wanted it, the guilt was so much.

"That happened over 10 years ago. We never talked about it. It's a closed deal for me, I had to live with a huge guilt and shame and I was so confused that night and the following days."

Many recalled how their experienced had given them long-term damage.

One admitted: "It ruined my life. It started with two curious kids and, eventually, it moved on to him never taking no for an answer whenever I went over to visit."

Sexual relations between cousins are not illegal and are not therefore classifed as incest; but some contributors to the thread recounted their experiences of such relationships. One man was defiant in his love and lust for a cousin: “I can't say I disliked it or I feel guilty or anything. It is amazing, she's hot and thinks I'm hot as well."

Another was similarly relaxed: “I had sex with my cousin when we were both 17. It was consensual and there were never any guilty feelings from either side. We only had sex the one time but I think it was because we both fell into long term relationships shortly after we slept together.

"Our relationship never changed after we slept together, this was over 20yrs ago and we still talk on a pretty regular basis with no weirdness.”

There was one surprisingly happy ending among the tales. One woman said: "My brother and I engage in it every day. We've been together for 6 years and have two kids. It started because I was horny and just wanted to get laid. Turned into a relationship.