Responses
Was it mentioned? I didn't notice if so.. Cause in real surrogacy two can make it to the egg that's why most same sex couples that wanted a child of their own went for surrogacy.
You could add two sperm to an egg in which you have removed the DNA. You'd end up with a child with just a bit of the donor's DNA but the fertilized egg would have the DNA of both parents.
What if they decided to use both semen so it wouldn't be unfair for yi yun?