My sister had my baby

A lady came in to the store and she seemed liked something was wrong..against my better judgement I asked if she was okay...she said that her husband had an affair with her sister..I said, "Oh no"...she then said that her sister got pregnant..I was hoping that she would stop there..I said, "What can I get for you"...she then said that her sister moved in with them because she was pregnant and she needed help...I said, "What can I get for you"...she said that the baby was hers..I said, against my better judgement, "I thought your sister was pregnant"...she said she is, but because she had sex with her husband that she gets to have the baby...I said, against my better judgement, "does you sister know this"...she said that she told her and that was that..her sister doesn't like it but it her husband so it must be so...I asked, against my better judgement, "does your husband know this"...she said she told him that it was her baby and he said whatever....so what I have learned is that if a woman is married and her husband cheats on her with her own sister and that sister gets pregnant it isn't her baby..she had sex with your husband and that means it's your baby...a + b = f...I also learned that sometimes you shouldn't ask questions because there simply are no good answers.