1. Phil Coulson is the Human son of Charles and Erik I don't know if he was adopted or is the bio son of one of them, in the fic Erik stops visiting and when Charles finds Jean and other young mutants he neglects Phil.
Phil ends up cutting contact and changing his name, later Charles "feels" Phil "die" and looks for Phil when he's found it's made clear he'd not welcome.
2. This one might be full on non-con in it I'm not sure but Charles is attacked and both Erik and Raven don't believe him and lose patience with him when he suffers PTS. Charles runs away from them they don't see him till years later when they see him with Tony Stark one of his mates from Uni, they go looking and Tony warns them off.
Hope these ring a bell and thanks in advance.