S3·E17 Loathe Potion No. 9

Boomer fears that Mikayla and Boz's budding friendship will blossom into a crush and he'll lose another brother to a Mikayla preoccupation. He gives Boz and Mikayla a Dirt Fairy potion so they'll dislike each other, but the potion is too potent and sends them into mortal combat instead.