Go with them(family secret route)

The park is serene and tranquil, with birds chirping in the trees and other people out having picnics. Your mom, dad, and grandma walk through the park trail, over bridges, and through fields of flowers. Your mom and dad had their arms around each other while Katherine had her arms around you.

"Aw, look at you two. So cute," your mother says.

Katherine giggled. "Do we make a lovely couple Jenna?"

"Oh, mom. I think it's time we tell James. Anna too when we get back home." Your mother sighs.

"Tell me what?" you ask curiously.

You and your parents and grandmother find a secluded place in the park and sit on a park bench.

"James it's going to be hard for me to tell you this, and I want you to understand, that I'm still your mother no matter what."

"This is starting to freak me out." You say. "Am I adopted or something."

"Mom, show him." Your mother tells Grandma Katherine.

You turn to your grandma who starts to lift up her skirt. You remember that she wasn't wearing any underwear so you know she is about to expose herself, but something catches your attention. Something...long.

"Oh good god! Grandma! Y-Y-You have a cock!"

Standing erect is a white flawless, pristine cock with a juicy red bulging tip. You aren't sure why you'd describe her dick like that nor how you didn't even notice it when you peeped at her earlier.

"James, look at me," your mother says.

It takes you a few seconds before you tear your eyes away from the 8-inch monster and when you do, you see something even more surprising.

"Mom! You have a dick too?!"

That's right! Your mother also has a dick! And she is erect as well, about 7 inches, the same size as you.

"This is our family secret, James." Your mother says. "We have both genitals, healthy and fully functioning."

"And that's not all," your Grandma adds, "Bob, show him your pussy."

"What?!" You scream in shock. You can't believe what you're hearing.

"Mother! That's not funny!" Jenna says.

"Hahaha, just kidding, dear. It was a joke." Katherine says. "But what I'm about to say next isn't." She turns to you.

"W-What is it?" you stammer, too afraid to find out.

"James. I am your mother."

"Eh?"

"I impregnated myself. I'm your mother and also your sister because we share the same DNA. Your mother Jenna is actually your Neice and half-sister that I had with your grandfather who is also your brother-in-law. Bob here is also your brother-in-law, and Anna is your granddaughter and niece from Bob and Jenna."

Your mind explodes from the sheer confusion that is inflicted upon you, but you strangely understand everything she says.

"It's a lot to take in Uncle Bro," Your mother turned Neice Sister says with a wink while jerking her cock. "I want you to take a few seconds before it all settles in. But be quick because we're going to start any minute now."

"Wh-What are we starting?" you nervously ask.

"Let's just say that **** doesn't affect our bloodline" Katherine says with a husky voice "and I'm still fertile." Your grandma slides one hand in your pants and starts fondling your balls. "Your Sister Mom needs her Brother Sons cock. Badly!"