HELP........

What am I suppose to do???? I walked in one day and my husband was sucking my sons dick, both of them butt necked sucking each others dick, my son is 20 yrs old has a beautiful GF and my husband hates gay people, I don't understand what I have seen, I watched my husband swallow my son's cum and I watched my son licking my husbands asshole and sucking my husbands dick till he cum in my son's mouth and he swallowed all of it.

They don't know I seen them but I really want to say something about it, should I tell them that I seen them
sucking each other off? or just pretend it never happened??

I just married this man 7 years ago so no it is not his son but it is his step son, I need to know how many times they have done this?, why are they doing this?

OLEASE HELP.........