My sister-in-law’s husband stopped having sex with her in her ninth week when he found out she was pregnant. My wife, Cindy, after learning of this she confided in me as to what was going on with her younger sister - June. She said that her husband Frank, although he loved her, just couldn’t seem to bring himself to have sexual relations with her while she was carrying their baby, out of fear he might hurt the unborn child.

This was driving a wedge in their marriage to the point that her sister was contemplating getting a divorce. Her sister, now at eleven weeks, was horny and just desperate for some relief from this crisis! My wife, worrying about her sister and her marriage, counseled her to masturbate but it seemed that this had been tried but was just not enough.

Both girls have an extremely high libido and as she was beginning to get larger, it was also not going to be easy for her to satisfy herself much longer anyway. So my wife drafted me to help with her sister’s sex life. I was really quite reluctant and very, very apprehensive about doing this but my wife kept on insisting and reassuring me that she was quite ok with my helping her younger sister out this way in her hour of need.

So the plan was set in motion. My wife and I would go over on Thursday to deliver a dinner dish while her husband was at work. It was very awkward for me and even odd as we sat around together the three of us as we nervously talked about this as well as other things knowing what we were about to do.

Suddenly my wife’s sister announced that “All the lights will be out, the room will be as dark as I can make it and we can just do the deed without touching each other elsewhere - okay?”

“OK,” I said, as my wife got up to leave so her sister and I could be on our own. We went upstairs to their bedroom and I stripped off my clothes and lay down on their bed as she removed her robe, climbed onto the bed and straddled me in the cowgirl style. Boy, she was soaking wet, but even so, as I tried to enter her, she was tight so it took a little work from her moving slowly up and down, for me to get my cock inside her wet little cunt.

She was even tighter than my wife had been in the beginning of our marriage, and this brought back wonderful memories of my wife’s tight little pussy back then. As she had said, the room was dark so I really couldn’t see her body as she was self-conscious about cheating on her husband and about how she looked in her pregnant state. That first time, after I had overcome her tightness, was really just bam-bam and too short for both of us I think. I came quickly as she seemed to be uncomfortable. The sensations on my erection were much more intense due to her tightness and, I guess, because of her pregnancy. She remained very apprehensive in the beginning that what we had done in their bedroom was wrong, but she did it anyway, her need was so great.

After we had finished, I got up, dressed, and went home, I told my wife that I didn’t think this was going to work out. I told her, “Your sister is extremely tight and it was hard getting inside her extremely tight little pussy. I think it was even harder with her than you were in the beginning and you remember how hard it was for us.”

However, my wife persuaded me to persevere as her sister said it was scratching an itch and helping to save her marriage.

By my fourth visit, she left a little light on and even allowed me to caress her breasts. WOW, a pregnant woman's breasts are so firm that they seem to be almost as if fakes, but WOW how I realized how much I missed a good handful of firm breasts. Not that my wife's tits aren’t gorgeous, but when presented with a full, firm pair, it is even more erotic and really such a pleasure to fondle.

Our sex together remained quick and not as wild as at home with my wife but the forbidden nature of it, and the risk of being caught made it somehow more sensual. We became more intimate as our sessions continued every Thursday and by the end, we were making love like any couple, the lights on and touching each other in all those sensitive places that we had promised each other, and my wife, that we wouldn’t. She remained extremely tight right up until to the end.

As her due date approached, we stopped until she had seen her doctor. The result of that visit was that if she didn’t go into labor naturally within the next two weeks, they would have to induce her. My wife and I both knew that the compound to induce labor is in semen so I was persuaded to forgo sex with either gal for a few days to charge up my reserves and then went to visit my sister-in-law on Thursday as usual for the last time.

I will never forget that day. All pretense at my visits just being a service for her needs had gone. We were onto each other like teenagers, tearing off our clothes and smothering our bodies with kisses. She got on her knees as she had done more and more as her time approached. It was much easier this way since she was so big with her belly so pronounced. We did it doggy-style on most of the last eight or nine weeks.

What a sight. I knelt behind her and staring at her swollen, dripping wet pussy lips just waiting to be penetrated. Not wanting to hurt her, I first masturbated to get as close as possible to an ejaculation and then, just before I was about ready to explode I enter her deeply as she sighed and pushed back onto me until I was fully in before shooting my load after only a few strokes.

WOW, what pleasure that was, just holding on to her hips, her glorious ass spread out before me as I pumped away until everything I had was deposited deep inside her as she cried out with a sigh of relief as I pushed a finger into her ass, her instant orgasm was a surprise to both of us.

She couldn’t thank me enough for helping her over this difficult period and reassured me that her marriage was secure and that was all thanks to me. And yes, twelve hours later she went into labor where she had a natural childbirth and produced a beautiful little baby girl.

Things changed between us after that, and every time she got pregnant, I knew what I had to do to save her marriage. However, I’m ashamed to say that just occasionally, no really, honestly, just occasionally, I would get into her panties and have sex with her. I like to think that this has saved my marriage too as sex for me is now much less frequent than it was at the start.