I am absolutely disgusted!

So tonight I found out on accident something that I would have rather never heard. Not because it was something completely disgusting but because I wish it would have never happened. I found out that at the age of 9 both my boyfriends sisters had been asked by an older man to kiss them. What makes it more disgusting is that older man is there father! What really gets me though is that there mother knows! How can she even sleep in the same bed with this man? Or stay married to him 10 & 2 years after this happened! It makes me so disgusted I don't even want to look at him anymore or even be in the same room as him!