My Little Pony: Friendship Is Magic (2010)

S2E5 Sisterhooves Social

Inspired by the bond between sisters, Sweetie Belle proposes a spontaneous festivity to honor their connection. However, when Rarity opts out of joining the fun, Sweetie Belle's frustration boils over, leading her to angrily renounce Rarity as her sister. The event takes an unexpected turn as emotions run high, testing their sibling relationship.