Stan's relationship with Dipper and Mabel's parents?
I'm confused on that front.
On one hand, Stan seems to be on good terms with them, and they with them. I mean, they allowed their children to stay an entire summer with him, so that means they do trust him quite a lot despite him not even being their actual grandfather. In the recently released video game, it's revealed Stan was present at the hospital when they were born, and was even one of the first people to hold the twins, showing that they must have some sort of positive relationship.
But then, there's the times where Stan says Dipper and Mabel are the only family he has left. And the signs that he's basically been on his own since he was kicked out of his parents' home.
So, where does that leave Dipper and Mabel's parents? And Shermy even? Does he not consider them family for some reason? I doubt there's antagonism there, or else the twins wouldn't be allowed in his presence. Even the worst parents in the world are hesitant to leave their kids with people they don't like. So, what gives?