I turned and fired a balloon back at Shannon, hitting her in the stomach. The bottom of her shirt quickly became translucent as it soaked up the water. Another balloon flies past Shannon's body, breaking behind her. We both turn and quickly fire balloons at Laura, hitting our target. There she stood with her shirt completely wet on the front and her large breasts revealed under the shirt.
I must have stood too long admiring my sister, as I soon felt the cool water from a balloon exploding on my chest, exposing my breasts for the others to see. Laura and I quickly spun and fire balloons back at Shannon, hitting her in the chest.
We continued to throw a few balloons at each other, but it seemed like a waste, since we were already wet and exposed. We call a truce and meet in the middle by the pool. Shannon reaches out and starts to massage our breasts with her hands, through the fabric. I looked at Laura and we acted like we are going to respond in kind. Instead, we simply pushed her into the pool.
We jump in after her and float under the water, admiring our naked bodies through the shirt fabric that has completely become see-through. We surface to catch our breath and to remove the now useless shirts from our bodies. I float over to Laura and press my breasts against her, as we lovingly hug. Shannon floats over and we allow her into our group hug.
The water is refreshing as we float on our backs. My breasts stick out of the water a little, exposing my nipples to the sun. As I open and close my legs to move, the water rushes across my pussy, exciting me. Even with the extreme heat, this extra attention was making me horny.
As I floated, I felt something hit the water next to me. The next one hit me squarely on my breasts as a water balloon splashed over me. I looked up to see Shannon's twin brother, Bret, standing by the pool with his hard cock exposed below a long white shirt.
All three of us began to swim to the edge and climbed out of the pool. Naked, we each grabbed water balloons and started chasing Bret. We pinned him against the pool edge and pelted him with balloons. He acted wounded and fell into the pool. We dove back in, helped him out of his shirt and took turns riding his hard cock.