彼の冗談に

at his jokes

→ 彼
phrase Rare #35,440
at his jokes The particle に marks what someone reacts to; the natural English preposition depends on the verb, as in “laugh at” or “be tired of.”
JA: 彼の冗談にみんなが笑った。
EN: Everyone laughed at his joke.

彼の冗談にはもう飽き飽きしている。

I'm already fed up with his jokes.

彼らは皆彼の冗談に笑った。

They all laughed at his joke.

クラスのもの皆が彼の冗談に笑った。

Everyone in the class laughed at his joke.

彼の冗談に笑わずにいられなかった。

I couldn't help laughing at his joke.