Originally Posted by pr0xyt0xin
I do kinda expect him to be his son. Magneto is at least 40 in this film, I'm quite sure his makeup will attest to that. And this Peters kid still looks high school age. He played the age range just fine in Kick Ass. So whether Mags knew about his son/daughter or not in First Class, he will find out this time around, and I doubt Singer will want to do it any other way than the right way. And maybe Fassbender isn't the father but McKellen. There's always that route too.
That would require a lot of explanation if they take the father-son route. There was no indication that he is a father in First Class and the original trilogy. In my opinion, make it simple and just make Quicksilver, one of his allies/henchman.