What’s the worst? That he had an affair with his late wife’s younger sister? She was white in all but name!
He freed their children, and allowed the older two to walk away into white society long before he died, giving them the money to do so.
He seems to have tried to do the best in a bad situation.
You seem very race-obsessed, here. I’ve made clear that I have some mixed ancestry myself. So, I’d suggest trying a different tack. What else might be offensive about your contentions?
Or, arguably, they married clandestinely according to natural law - she being a free woman in Paris at the time.