A love story (robdip)

This AU involves: Dipper is 16 and Robbie is 17

Who thinks that two boys who hated each other for 4 years would actually start to like each other? Not me. But I think that's because I think of other things.
A royal ball is being hosted at the Northwest mansion and Pacifica invited Mabel, Grenda, Candy, Dipper.. And Robbie. Pacifica, Mabel, Candy, and Grenda all joined in as a group and are now trying to pair them together.