@alyx its actually still tsundere, since the term really only specifies flipping between those two states, not in which order :)
"The word is derived from the terms tsun tsun (ツンツン), meaning to turn away in disgust, and dere dere (デレデレ) meaning to become 'lovey dovey'." - https://en.m.wikipedia.org/wiki/Tsundere
Welcome to your niu world ! We are a cute and loving international community Ｏ(≧▽≦)Ｏ !