I want to point out to my wife she is not genetically related to her father
Wow, you seem to really hate your wife's father. What happened?
He and I have butted heads ever since my wife first introduced us.
This is a sensitive subject that you shouldn't use as a bludgeon. In fact, you shouldn't touch this subject unless the father forces your hand.
Fuck him. He deserves this.
Even if that's true, it's not your place to air family secrets like that.