Zev’s every action in the beginning is motivated by her singleminded love for Kai and her desire to keep him “alive.” That pressure is off after the movies and “Mantrid” and as she gains self confidence and Kai continually rebuffs her, she seeks physical satisfaction elsewhere. She doesn’t seek “love” elsewhere because she still loves Kai. She also becomes warmer and more considerate to Stanley, but it’s friendship between them, not love.