You might want to read the first part if you haven't. http//www.literotica.com/s/fall-folly
If not I think they stand alone. Yes all are over 18 they always are in my stories.
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Melani felt sick to her stomach and revulsion at herself instead of the afterglow of a good orgasm. She had just masturbated to her nude son while he masturbated under the outdoor shower. Her shame quickly turned to anger at him for being that perverse to jack off in a public place. She wanted to go tell him off and tell him how terrible it was but she couldn't without telling him she was watching him. She was angry at him, angry at herself for watching him and touching herself, even though she didn't know it was him until it was all over. Melani was flushed bright red from head to toe, not in orgasmic bliss this time but in rage and confusion. Even in all her denials when she saw her sons face she felt another and maybe the best jolt of joy and she wasn't even touching herself there. Still nude Melani felt chilled to the bone and now nauseous again. Running from the room to her bathroom she nearly tripped on her robe laying on the floor and forgot to close the door completely as she raced out to find the toilet in her bedroom so she could be sick.
Melani had missed the tail end of the mud caked boys conversation where Blake told Robert that he was kinda nervous about taking a shower outside and Robert let him use the shower in the mudroom while he took the pool shower. Robert knew it was private, well except for the view from the guest room but nobody was ever in there.
Robert stepped under the water and stripped off his shorts at the same time. He was glad this was Florida and he could do this most of the year. If he could get away with it he would shower out here all the time, he liked the way if felt to be outside naked. He began remembering last June when he and his Dad had put the shower in. His Mom had wanted the shower in pool house but his Dad didn't want to break up the concrete floor to put in a drain and increase the cost. The hard part was the trenching for the water lines. His Dad was cheap and didn't want to rent an excavator to cut the trench so Robert Spent all Day Saturday digging from the garage and running the water lines to the shower. Hot on one side of the trench and the cold on the other. Fortunately his dad used PVC flexible pipe so that had all that done in one day. Sunday they built the shower frame,installed the drain, and put the privacy wall along the pool house wall. A weather front moved in that afternoon making finally connecting the shower impossible in the frequent thunderstorms. So Monday morning he was outside finishing the shower for his Dad.
It was almost finished the task and was still tinkering with getting the shower head adjusted right when he heard the scrapping of pool furniture across the concrete pool deck. Looking up over the wall he saw his mother lining up her pool side lounger for the optimum sun exposure. He guessed she was out for the sun because she was wearing a bathing suit he had never seen her wear before. Instead of her normal Mom one piece she was wearing a very skimpy thing bikini. From behind Robert could see the toned tightness of her thighs and ass with it rounded shape with little indentations. At first he ducked behind the wall blushing a bright red. He did not want his Mom to know he was there. He knew she would be so embarrassed.
When he knocked the pipe wrench over and it clattered across the wooden floor he cringed in fear and froze waiting to hear his mother call out "Who's there?" Instead he heard nothing except birds chirping and the wind in the tree branches. Peeking over the wall he looked at his mother who was now laying on the lounger face down away from him. Her left foot was slightly bouncing to a tune that playing in her head, literally. Robert saw she had her MP3 player with the ear buds in her ears. Relieved Robert went back and finished the shower installation.
About 20 minutes later Robert was done, the tools in the tool pouch, and the shower worked perfectly. It wasn't designed for full naked bathing shower so it was only enclosed on 3 sides. It was meant to let people wash off the pool chemicals when they were done swimming. Robert peeked back over the privacy wall and was relieved to see his mother had her head turned away from him toward the back fence. What he also saw made him gasp and freeze in place. Her legs now raised at the knee with her calves bent back over her thighs. Her calves were crossed and she appeared to be doing some kind of exercises as the muscles in her calves, thighs, and ass flexed. Robert had seen enough internet porn to know that his Mom was masturbating. Her left hand was hidden underneath her and her right arm was was grasping the top of the lounger, the ear buds still in her ears.