He poured a second cup of coffee, sitting nude at the kitchen table and smiling as his wife drove away early on that Saturday morning to get laid. She’d dressed lightly and given him a loving kiss as she left. She’d be back for lunch, happy as could be, he knew from past experience.

The male organ between his legs began to swell as he thought about what would happen between now and then. It was partly the idea that his wife of twenty years would be joyfully naked with another also naked man, repeatedly enjoying all the pleasures such a situation can provide. But it was much more personal than that.

The garage door opened and a lovely woman a few years older than himself entered. Her smile was as big as his as she provocatively undid her sundress and dropped it to the floor, revealing a lack of any underwear. Now his tool was fully filled viewing the luscious mature breasts and lightly furred triangle.

With no need for words they went to the guest room and started fooling around. A half-hour later, sated for the moment, they sipped coffee and caught up on each other’s past week while they took an intermission.

Once again joined in passion, the lovers moved together, changing positions with practiced ease. The tempo built to the expected finale and they lay quietly, still genitally joined, resting once again.

The woman spoke softly, “I remembered that it was five years ago this weekend that we four skinny-dipped for the first time. My sister and I both had exactly the same idea, we were pretty close in many ways, when we saw the two erections that our naked bodies produced. For fifteen years I’d had trouble climaxing because my husband’s cock was too long to fit all the way in. Sis had the opposite. Your shorter, thicker one didn’t fill her all up.

“Swimming was forgotten while we tried each other’s husband out. That worked! You got me off with your pubic bone on my clit and she got her cervix rubbed to orgasm. Our every-weekend and vacations-together plan has worked pretty well.

“Who’d have thought that two brothers and two sisters could be built so differently yet work things out so well?”