Timmy is a cuck just like Dad

"Your sister is very beautiful, isn't she?" I ask with a patient smile.

"Y-yeah." Timmy says, looking down and not meeting my eyes.

I grab one of his shoulders. He slowly is able to look me in the eye, his semi-erect penis shriveling up.

"It's okay to enjoy watching. Your old man likes it too!" I declare.

"R-really?" My son asks hopefully.

"Yep. In fact, I was coming right up the stairs to take the exact same position your in. To watch your sister taken by a big, hard, powerful cock." I look down and see my son's cock growing hard again.

"Do you wanna get back to the show?" I ask.