Kim notices you spying on her

Kim, before turning off the lamp, ended up looking towards the door and froze. You were sure she had noticed the door was ajar and that there was someone there.

You tried to leave in silence so as not to draw anyone's attention and hoping your older sister wouldn't realize it was you, but the bedroom door opened wide behind you.

"Will, get in here. Come quickly before someone sees us." Kim said

When you turned around you saw that she went in such a hurry to the door that she didn't even have time to get dressed, because her dick was fully exposed hanging in front of her.

You entered Kim's room and she closed the door, locking it. Your sister then sat on her bed and asked you to sit next to her, which you did.

"Yeah, now you know my secret, right?" Kim said

"It was really a surprise." you said

"You must be disgusted by now, right? You sure are disgusted to discover that your sister has a huge dick." Kim said, tears starting to run down her face

"Calm down, no need to cry. I'm not disgusted with you. Yes, it was a surprise, but you're still the sister I love, whether or not you have a dick between your legs." you said

"Are you serious?" Kim asked

"Very serious." you said

"You are really kind Will." Kim said, hugging him "I'm glad you took it so well, but I need you to promise me something. Please don't let Mom know that you know our secret at all."

"?" you asked

"I was already suspecting that Mum has a dick too, since having one is genetic, not to mention I think Alice might have one too, but why can't Mum know that I know?" you said

"It's because she had some bad experiences about it. It hurt her a lot and she is so terrified about the matter that she has forbidden me and Alice to let you know about it." Kim said

"Do you know what the bad experiences were?" you asked

"I don't know all the details, but Mom told me that all her old boyfriends dumped her as soon as they discovered her dick, so when she met our dad she hid it as best she could from him, but when he found out the truth, Daddy got into a big fight with her and left us." Kim said

"How did Mom manage to hide this from Dad? If we exist it's because they had sex, and because of our age difference they stayed together for years." you asked

"She just had sex with him in the dark and being careful he didn't get all over her dick, which wasn't easy since hers is so much bigger than mine, and after Alice and I were born she wouldn't let Dad change hands. our diapers." Kim said

"And how did he find out?" you asked

"He found out everything because of me. I couldn't sleep one night and I went into their room to sleep together and I turned on the light when I entered the room but they were having sex at the time and Daddy got mad when he saw Mummy's dick." Kim said

"I see, it must not be easy for her to open up to another man. If you have a problem with me that I am her son, it is certainly complicated." you said

After that, you and Kim were sitting there, not saying anything, her still with her flaccid dick resting on her right thigh. You realized your own dick was hard, just looking at your fuck sister was enough to give you an erection.