A slightly different twist to breedy-
The wife is very bi, and has a cum fetish, to include licking my cum from other womens' pussies.
There was one couple we had met and gotten to know at swinger parties. They always played with condoms which was cool with us. About six months later they told us only he was fucking at the parties, because she was off birth control as they were trying to have a baby. She was limited to just oral sex.
Well, at one particular party he hooked up with a lady and went to the back bedroom to play. I was on the couch in the living room, and my wife was giving me a blow job. As soon as he left his wife came over and ask my wife if she could help.
For a few minutes one would lick my balls and the other would suck my cock; occasionally trading off. I was rock hard and in heaven!
The other wife stopped and whispered something in my wife's ear. My wife got a big smile, and grabbed my cock. The other wife stood up, and my wife guided my bare cock into the other wife's pussy as she lowered her self on me.
It was a huge rush having my wife guide my bare cock into another woman's fertile pussy. At first I thought my tipsy wife had forgotten the other wife was not on birth control, until my wife told me to "give her a baby"
We saw them at two more parties. Each time she would sneak at least one load of my cum into her pussy when her husband wasn't around. They quit coming to parties. We heard that she had finally become pregnant. Never saw them again.