tease, play with
揶 centers on light, playful interaction meant to provoke a reaction: teasing or playfully messing with someone.
揶 combines 扌 (hand) with 耶, which likely contributes the sound. The hand radical suggests an action, fitting the meaning of teasing or playing with someone.
The hand radical 扌 beside 耶 suggests using your hands in a playful, teasing way—like poking or gesturing to get a reaction.
For ヤ, imagine a teasing 'yah!' sound as you playfully poke someone: yah -> ヤ, and your hand does the teasing.