Am I Overreacting from learning my bio father is a pedophile?

He is 81. I am 35. My mom was 24.

I only found and knew the man in the last couple of years. He used me financially and when I cut off paying all his bills, he got on a plane and left me with having to pay the bills on the home I bought him: now sold at a loss.

So. I like my bio family, him aside. They are great.

We are in a disagreement. My first with this side of my family.

So. They told me after he moved out. My older sister--my only known sibling from him--is 55.

She told me that she found her birth certificate. That her bio mom lied to her all her life about her age. Thing is, we did the math. Her mom was 16 when she was born. He was 26, possibly 27!

He married her one month after finding out she was pregnant.

Then MOVED OUT TO PRETEND TO BE HOMELESS IN THE WOODS a month after my sister was born.

The family says times were different then? That this was "normal" back then?

I say it is pedophilelia.

As a survivor of this abuse it really hit.