
Because you said that since they aren't blood-related, you don't consider them family. But it's not the blood relationship that pushes people to call each other family. Little Potato considers the Boss to be his parent, so much so that he calls him "Mama". And the Boss is taking care of him, as if he were his son. They are family

In real life i cannot accept any type of incest, if it’s manga then im meh about it since i separate reality and fiction. I think the best way for me to describe wolf king and potato’s relationship in my understanding is, the “drink from sake cup” type of family, not the “sign adoption paper” type of family. I dont know, maybe it’s just me that is so specific about these things in fiction and fictional characters.
Speaking about specificity, i dont know if u guys can understand this but time in manga or comics is not noticeable so there’s nothing to grow attach to. I cannot feel and see the family bond, just changes from a to b so i really dont mind these adoptive family falling in love trope. But in reality, movies and novels, we see the progress and be with the people and characters each step they take, which can make me be more attach to them, and so makes me unable to accept any form of incest. Basically my conclusion is the context of ‘incest’. Sorry if it’s difficult to understand what im trying to say, english is not my first language *cries*
Am i the only one who will only be bothered if it’s real incest? They’re not blood related so I never see them as father and son, just a person who saved a kid and is helping him because the kid is vulnerable. So i dont mind where this story will lead to, whether it becomes bl or not. It’s wholesome and that’s what matters.