Oh wait so you're not even married? I didn't realize you've only been together 9 months.

I would say kudos to you for trying to be understanding and sympathetic towards his situation but this is the kind of issue that destroys even the most devoted and long standing relationships. Such a serious problem as this is absolutely no foundation on which to lay the beginnings of a happy and fulfilling relationship. You deserve a lot, lot more. Serious deception and incest are not the sort of thing we expect from a relationship not even a year in the making.

Please leave this man to his problems - colluding in them could make it a lot worse and damage you in the process. If you don't have any kind of commitment tying you to this person then i reiterate getting out now before things become more complicated.