I think they have to find out for sure and hello, deal with the truth.
The “marriage” is sinful and it is their parents’ faults. It is not the kids’ fault but, as always, if you don’t follow Biblical Judeo-Christian boundaries, the kids pay. So, since he fathered these children and loves them, my advice would be, find out the truth, when everyone is old enough, reveal it, meanwhile, move into a separate bedroom and keep the kids happy. Oh and be sure to tell the lesbians who caused the whole entire fiasco by their selfish and shortsighted actions and emphasis on themselves and their sex lives.
It must be the Lawyer gene.
Seriously, your cavalier and judgmental comment, or should I say decree, seeks to punish all for the sins of the two lesbian couples.
Somehow, these two children of deviates managed to develop normally as heterosexuals and until the hidden facts came out, were leading a normal and respectable life. This isn't like an Oedipus story, for heaven's sake! Let them live out their lives as normal folks!