Aysha Paige - Mom Impregnated by Son

I just found out my husband is infertile... I never thought this would be an issue for us as we conceived our son with no issues. I don't know how to tell him... I know this will break his heart knowing we can't give our son a sibling. I was so upset and my son was just there and I told him everything. He offered something that I never thought I'd EVER consider... but what else am I supposed to do? I really want to give him a sibling.