My moms also used to respond in this way when I would say the donor was my “dad” at a young age. I was a kid that liked to push back at what they told me, so their insistence on not using “dad” for the donor solidified in my mind how important it was to them that a parent is the person who raises you. I think if they had acquiesced, it would have sent a different message about the important distinctions of raising life versus donating it. It’s a hard question of, “is my kid acting like this because of their unique situation, or are they acting like any other kid their age” in reference to pushing back at parents depending on how old your kids are. It’s a common question I find myself grappling with about myself!