Stancest are in a secret relationship and they really don't want the kids to find out. Well it's mostly Stan because Ford has forgotten what is ethically okay for children (and anyone in general) to witness. Both Stan and Ford are okay with giving a child (Mabel) weapons, but Ford has forgotten that it's wrong to do that and Stan thinks it's funny (he jumps at the opportunity to sell footage of Mabel and Dipper fighting he doesn't care at ALL). But when it comes to something that could actually be traumatizing to the children, Stan will try to make sure they don't see anything.
Stancest, in trying to act as platonic as possible, have accidentally tricked the kids into believing that they're fighting again. Ford keeps referring to Stan as his platonic sibling that he loves a lot but not that much because that would be unethical and Mabel asks why they don't love each other anymore and storms out the kitchen dramatically. Dipper reaches out for Mabel, looks back at the confused twins, and shakes his head disapprovingly and goes to comfort Mabel who is currently in sweater town. Ford asks if it wasn't something he said and Stan just puts his head in his hands because for someone so smart he can be so dumb. Ford sleeps on the recliner that night.
Soos is also distressed at Stan and Ford's current situation (he also thinks they hate each other).
Wendy walks in on them making out and is now on a higher payroll (blackmail baby). She reassures Soos that Stan and Ford don't hate each other, trust her dude, okay? Because Wendy has seen things. Wendy has seen things.
