Why does two bit laugh when pony picks up the glass?

Two-Bit laughs when Ponyboy picks up the glass because he finds humor in Pony's nervousness and the awkwardness of the situation. Ponyboy is trying to assert himself or engage in a social interaction, but his actions seem clumsy or out of place, which elicits a light-hearted reaction from Two-Bit. This moment highlights the camaraderie and playful teasing that exists among the characters in their friendship.