If family was all about keeping each other safe because telling them something would hurt them, then--

--well, okay, Billy would be guilty of it, but still. It kind of sucks to be thought of someone that needs to be shielded from something. It's not like there's much Erik can do that will shock him. Personally, now, maybe. Intellectually, he knows the sorts of things Erik can be capable of if he keeps going down the wrong track.

"I believe you made a mistake and you've paid for it, but...you can't decide what you want or don't want me to know because you think it'll be better for me."