Ever since it raised it's ugly head in The Amazing Spider-Man #509 the Sins Past story line has gotten a lot of hate. Whether this is justified or not is a discussion for another time but what isn't in doubt is that Gwen Stacy sleeping with Norman Osborn made for a WTF moment of epic proportions.
When Peter receives a letter from his long dead ex-squeeze, little does he know the horrors that lay ahead of him. Confused and looking for answe's he visits Gwen's grave only to be attacked out of the blue by two masked assailants who lay a beating on him before he can escape, a pattern that is repeated every time they meet.
Through DNA testing it is revealed that these new villains are in fact Gwen's children - Gabriel and Sarah - who are convinced that the web head is their father and had abandoned them, but the truth is far worse than that. Having been sworn to secrecy MJ finally confesses that Gwen had gone to see Norman when he was at his lowest ebb and gave him some sympathy sex. This led to her falling pregnant and to everyone reading the story to shake their collective heads in shame.