interesting thought. I would say depends on the situation and context....
as others have mentioned, once ****** found out that she cheated, everything would be over.
OTOH, if she could be pregnant "in secret" and the baby just show up, then that might work as could pass it off as adopted.
oddly enough, I was having this conversation with her yesterday. I say I was having it because she was ******* of the intentions. She was talking about possibly wanting to have another kid and we could try to reverse my vasectomy, somehow extract my sperm or adopt. I ruled out the vasectomy reversal as not doable... i know some claim it can be done. I told her the extraction was expensive but I also I ruled out adoption saying.. " I think it should be at least one of ours vs none of ours". I then said she would have to find someone to be the donor to have it with. I still think it went over her head though.