Dave and I (Stephanie) had decided a while back to spend New Years Eve with our neighbors, Jen and Ken. Since they had moved in next door to us a couple years ago we had hit it off quickly, and were like old friends.

Jen was an attractive, brown-haired woman, with a trim swimmer's body that I was a bit jealous of, with my well-rounded hips that my mother described as "made for makin' babies" (thanks Mom). Fortunately, my breasts were also larger than average -- Dave says they're my best part!

We had been drinking quite a bit, and the doobies were rolled before 10:30. We were sloshed and baked in no time. The guys headed off to Ken's computer room to watch some porn videos he had downloaded, and Jen and I were left to our own devices.

Jen had really lost her inhibitions by this point, and the talk quickly turned to sex. She was surprisingly ribald when she cut loose! After a few minutes, our conversation turned to birth control, and I mentioned that Dave had gotten a vasectomy because we wanted to remain DINKs (Double Income No Kids). Jen was quite interested, as they, too, did not want kids, and were using condoms for birth control. She then mentioned that she had never had sex without a condom. I was surprised, but she said the pill caused her to gain weight and she didn't like the idea of diaphragms or IUDs.

"Oh, Jen," I told her, "it feels so good, skin on skin, the way it was meant to be. To feel his penis shoot inside you. No stupid rubber to get in the way." She sighed, looking wistfully towards the computer room. I knew what was going through her head.

I sat closer to her. "Why don't we jump 'em at midnight?" I suggested. "Swap partners."

She turned to me, her eyes bloodshot from the pot and booze. "Oh, Steph, are you sure? I really want to, but I don't want to jeopardize our friendship." She held my hand, her eyes pleading.

I thought about her husband Ken, blonde-haired, with a nice physique. His hair had started to recede, making him look older than his 30 years, but he was a good-looking man. I had no misgivings about having sex with him. In contrast, Dave was dark-haired, with a little bit of a gut, but also attractive (I married him, didn't I?). As long as it was a one-time thing, I had no problems with him sexing up our neighbor.

"Let's do it," I urged her, "But Ken will have to wear a condom." I had stopped taking the pill earlier this month, but better safe than sorry.

"Oh, yes." Jen paused, considering. "Dave's vasectomy is 100% safe, right? This is my fertile time of the month. I guess that's why I'm so horny."

Suddenly I flashed back to our conversation with Dave's doctor. We still had to go back for the sperm count tests. He said that for a few weeks after the procedure Dave's reproductive tract could still have sperm in it. It had been only a week since the vasectomy and, due to some swelling, this would be Dave's first "post-snip" sex. There was a chance that he was still potent!

To this day I still don't know why I did it. I paused and thought about what might happen, and felt no guilt. I just looked into her eyes and lied, "Perfectly safe, hon."

It got closer to midnight and the guys came back into the living room, trying to disguise their hard-ons, caused by the computer porn. We refreshed everyone's drinks and waited for Dick Clark to count us down.

"Ten ... Nine ... Eight ... Seven ... Six..." We stood up and put our arms around our spouses. We were in a line, with Jen right next to me, the guys on the outside.

"FIVE ... FOUR ... THREE ... TWO ... ONE..." As we had discussed, Jen and I quickly swapped places, and planted a huge kiss on our neighbor's lips as everyone in New York screamed, "HAPPY NEW YEAR!"

None of us were paying any more attention to the TV, as the men's initial shock was quickly overcome by passion. Jen was already rubbing her jean-covered crotch into David's, and he looked over at me to make sure things were okay. I gave him a little wink as my tongue found Ken's.

After a few minutes of rubbing and caressing, before things went too far, I broke off the embrace. "We should talk to our husbands, Jen." I took Dave's hand and pulled him into the kitchen. Jennifer was going to tell Ken about David's vasectomy and I didn't want my hubby correcting her. I explained to Dave that he could have sex with Jen, ONCE and never again, as I would with Ken.

"But what about birth control?" Dave asked me. "Remember, I'm not completely safe for a couple weeks, at least."

"Ken will use a condom. Lucky you, you don't need to worry about it."

His horny mind filled in the blanks as a huge shit-eating grin split his face. He probably thought she was on the pill, the shot, or had a diaphragm. Men: so easily led by the dick.

We headed back into the living room. Jen gave me a nod. Ken's eyes were all over my body. We headed to their bedroom.

Clothes were torn off and flew everywhere as we jumped onto the bed. Ken went down on me as I reclined onto the pillows, and Jen pushed Dave onto his back, climbing on top of him. She straddled his hips and was so horny already that she easily got his dick inside her, slowly sinking down until their pubic bones met. Both of them groaned from the pleasure. Dave was in heaven, not even moving as he stared at Jennifer's beautiful features. She arched her head back, her mouth open. She paused there, just savoring the feeling.

"Oh, God, Steph, you were so right. It feels so warm inside me. I can feel so much of it." Jen looked down at Dave, then lightly bit her lower lip as she slowly started moving up and down.

Ken, meanwhile, was giving me a good tongue-lashing. That, in combination with seeing my friend enjoying my husband so much, sent me quickly over the edge.

"Unnh ... UHHHH! AUHHH!" I arched my cunt into his face as he dug in, giving my clitoris extra-special attention.

As I came down and opened my eyes again, I saw Jen arching her back again, gasping, "Oh oh oh". She was cumming herself, holding her body perfectly still as she enjoyed the sensations. David hadn't cum yet, and continued to adore Jen's lithe form astride him.

Ken climbed up on top of me, and I felt his penis easily sink into my well-lubricated hole.

I looked down in shock at his bare prick going into me: "Ken, you need a condom!"

"Dave gets to fuck without a condom," he replied, pushing in further.

I paused, choosing my words carefully, so as not to clue Jen or Dave in to the danger she was in: "She can't get pregnant from him. I can from you!" I tried to push Ken off.

He held up a hand with a foil-wrapped condom. "Relax. I'll put this on before I get close."

I looked over at Jen and Dave. They had stopped, looking at us. I looked down at where they were joined together, imagining his throbbing cock, so close to cumming inside my clueless girlfriend, possibly impregnating her. I couldn't break the mood!

"Okay, but ... be careful!" I stopped trying to push him away. He thrust all the way inside me, causing us both to grunt, then slowly withdrew halfway. Then he pushed in again, but not too fast. It really did feel so much better without a rubber...

No longer distracted, Jen returned her attention to riding my husband's possibly-still-potent cock. I could see slickness around his shaft when she pulled up; she was so wet! David reached up and fondled her smaller breasts and she gasped, caressing his hands, urging him to squeeze harder. She bounced on him faster, more urgently.

Ken's mouth found my nipples, and sucked them in greedily. I gasped, arching my back, and closed my eyes. Ken's thrusting was getting more insistent.

I felt someone take my hand. It was Jen. I turned to look at her again. She was almost glowing, so beautiful, and I held her hand as she bounced up and down, harder and harder.

Suddenly, my husband cried out as he came: "Unhh ... aahhh ... ARHHHH!!" He grabbed Jen's hips and thrust his pelvis up inside my misled girlfriend. In my mind's eye I could see his semen, chock-full of potent sperm, spurting up inside her fertile vagina.

Set off by his eruption, Jen also came hard: "UOHH! I can ... feel it! UHHH! OH GOD! So hot! So wet! UH! UH! UH! UHHH!!!" She bounced in my husband's lap like a pile-driver, urging more and more of his cum into her.

Her hand squeezed mine hard as she orgasmed, and the combination of Ken's thrusting, sucking, and seeing the unsuspecting Jen possibly impregnating herself on my husband pushed me over the edge, hard: "OHH! OOOHHHH!! OH JEN!" I couldn't take my eyes off the bouncing woman's pelvis as Dave's excessive cum leaked from her vaginal lips and down his penis. My orgasm felt like it wouldn't stop.

I had been so distracted by the reproductive possibility next to me that I had forgotten my own danger. Ken thrust up inside me hard, crying out:

"Aw fuck! You're sucking the cum right out of me! UHH! UAHHHH!!" he yelled.

The tickly, pulsing feeling of his semen spurting inside me kept the orgasmic high of my overheated body going, and I screamed: "NOOAAAAHHH!! NUHHHH!" My mind feebly attempted to wrest control, but my body was having none of it. I was in the middle of my fertile cycle too, but thought I would be safe with a condom. There was a chance that there were still enough protective hormones in me from the birth control pills I stopped taking earlier in the month, but only a small one. Ken was drunk and stoned, and didn't care that he could be impregnating me. My spasming pussy sucked more and more of his dangerous seed inside me as my uncontrollable pelvis jammed back against his.

How the hell had this gone so wrong?

What was done, was done. Turnabout was fair play, I mused, once I returned to coherent though, although I was still pretty stoned, myself.

Things got a little uncomfortable, what with Ken's carnal faux pas. Dave and I left for home shortly thereafter.

My period came a week later, thank God. Guess whose didn't?

End of part 1

Jennifer couldn't believe it: she was pregnant!

The pregnancy test was positive. How had this happened? Ken always used a condom when they had sex.

She sat down on the toilet seat cover, burying her face in her hands. She didn't want this, but her strict Catholic upbringing, while not a large factor in her life anymore, just couldn't let her have an abortion.

A trip to the doctor confirmed it: about a month-and-a-half along. She had missed her first period a couple weeks after New Years, and when she missed it again the next month, she bought the pregnancy test. But that meant that New Year's Eve...

Her mind flashed back to that night. She remembered her friend Stephanie getting fucked by Ken, and herself bouncing on Stephanie's husband Dave's cock. They had fucked each other's spouses, without condoms, although Ken said he came inside Steph accidentally.

Steph had told her that Dave had had a vasectomy! He was safe!

Later that week, Jennifer visited Stephanie and Dave. She got Dave alone and asked him about the vasectomy -- Ken was considering one, she covered -- when did he have his? A week or so before New Years, Dave told her.

Jennifer later asked Stephanie about her period. No problems, Steph replied. She had been worried about Ken cumming inside her when she might have been fertile, but she had gotten lucky; "Aunt Flo" came to visit right on time.

Stephanie knew not to ask Jennifer about her period, as even cursory interest might cause the woman to suspect the trick that had been pulled on her. Oh well, she thought, I guess we'll all find out soon enough...

Jennifer researched vasectomies on the Internet and found that a week wasn't long enough to start having safe unprotected sex! No self-respecting doctor would have kept that information from his patient or their wife; Stephanie lied to her, and now she was pregnant with Dave's baby!

She was furious! How could her friend do this to her! The more she thought about it, the angrier she got. It wasn't really rape; she had wanted the sex, just not the sperm!

She told Ken about a week later, once she had calmed down. He could count back just as easily as her, and rushed for the door, meaning to go next door and beat the crap out of Dave.

Jen stopped him and revealed her plan. He calmed down, but there was a gleam in his eye. Revenge...

Jen and Ken visited Dave and Steph several times a week after that. One evening, Dave was on his back, working on the underside of the furnace in the basement when he felt a touch on his inner thigh. His head went up and banged into the metal. Wham!

"Ow! What the hell--?" Dave squirmed out from under the furnace, still on his back. Jennifer was there, knelt down, her hand now moving higher up his thigh. "Jen, what--?"

"Oh, Dave, I can't stop thinking about you, since New Year's. You felt so good inside me..." She blinked her long lashes at him.

Dave was taken aback. She hadn't said more than a few words to him since that night, and he thought she had been weirded out. So she had just been shy about her true feelings for him! He rose up to try to kiss her.

She turned away. "No, Dave ... I ... I can't ... not now..." She got back up, and he was left with a good view of her shapely behind as she stole back up the stairs.