What should I do if I find out the secret of my husband and ex-girlfriend opening a house?

Face this problem rationally, this problem is a mistake that most men will make. If this man already has a marriage certificate with you, you can turn a blind eye, or you can have a good talk with him and see what he thinks inside. If it is a moment of confusion, you can forgive it and pretend it never happened. If they still have feelings, you can choose to leave without children.