godan verb (-u)
poke each other; jab each other
Describes two or more people poking or jabbing one another, often playfully or in a light physical interaction.
子供たちは指で突き合って遊んでいた。
The children were playing by poking each other with their fingers.
彼らは冗談で脇腹を突き
They jabbed each other in the side as a joke.