Dipper is far, far too real for them to ever pretend that he was dead. And, to be honest, they could never do that. They love him too much for that. Mark and Anna have a very difficult and strained relationship with Dipper, absolutely, but they can never fool themselves in thinking he’s dead.
(also for the sheer amount of pictures with triplets being held in empty air and occasional ones where dipper shows up that Mabel sends them like- no denying Dipper is around.)
As for the triplets- things are definitely very awkward with Mark and Anna (especially after California).
But.
But Mark and Anna love Mabel and Dipper, and of course love the triplets. There is no denying that. The triplets are their only grandchildren, and ofc the kids aren’t going to see Arnold and Rita.
Once or twice a year, Mabel and Henry send the triplets to visit Mark and Anna for a week. It keeps Mark and Anna from having to come up to Gravity Falls too often and deal with…. awkwardness, and it lets the kids get to know their grandparents. And to be fair, all parties involved usually have a good time. Acacia loves going to Grandma and Zaydee’s house because there’s a sweet tree in the backyard she can hang out in (Mabel is very salty that Anna lets Acacia climb that tree when she never could but #grandparents). Hank by age 4 had befriended the entire neighborhood and loves seeing his California friends. Willow…. Willow can see the lingering colors in the house, in her grandparents’ auras… so it’s harder for her. But she does love cooking with Grandma.
There’s a distance, between Mark and Anna, and their grandchildren, and their children. It’s a distance that is only partially bridged. At the end of the day, if you pushed the triplets, their true grandparent would be Stan.
It’s not perfect.
But its better than nothing.
