[genedad]

We all froze when we heard Marc. Uncle Bob and I pulled up our bathing suits but Dawn was still naked on her knees.

"I thought you were protecting her from dirtbag boyfriends, " he said looking at me. "What should I say to Mom and Aunt Joyce." Looking at his uncle and his sister.

"We aren't harming anybody and we are just having fun. I love your sister and she loves me. Uncle Bobby has done a lot for all of us. If I don't mind what Dawn does, why should you."

"She's my sister."

"And she's my girlfriend."

"You two do this before? With others?"

"None of your business, but yes. Your sister is very sexual and very desirable. We enjoy sharing with others. Don't you think she looks great?"

Marc is thinking. He says," If I don't tell Mom, what will you do for me?"

Dawn said to her brother, "look it, I can't fuck you. I promised Gene. Can I do something else?"

Marc walked over to his little sister, opened his zipper, pulled out his cock and told her to open her mouth. She didn't want to, after all this was her full brother. This was in_est. realizing she didn't have a choice she started. Marc was a mechanic, who could have had much better personal hygiene .

Dawn looked at her brother and said,"Your cock tastes like piss. Don't you ever wash?"

This made Marc angry. "Just suck my cock. It looks like that's what your good for." He put his penis back in her mouth and started face ducking his little sister. He is way to rough and she is gagging. Suddenly he pushes hard. I can see her throat bulging from the outside. He shouts that he is coming and literally comes down her throat. Dawn pushed him away.

"You jerk. That hurt and it wasn't fun. You didn't have to be so rough. I'm your little sister."

"No you're more like the family sl*t." He hit the ground. That's right, I sucker punched him. I hit him as hard as I could in his stomach.

"Don't ever talk like that to her again. She offered to take care of you and that's how you act. You try saying anything to your Mom or Aunt Joyce and Dawn will say that you attacked her. She'll say she was here alone and you came in and forced her to give you a blow job. Why don't you leave."

Marc got to his feet still holding his stomach and left. Dawn and I said good-bye to Uncle Bob and left as well