人命关天——我们可不是在开玩笑。

Someone's life is at stake - we're not ___playing ___games.

债权人警告说，他们对逾期付款这件事可不是闹着玩的。

The creditors warned that they were not ___playing ___games about the overdue payment.

别再兜圈子了，关于合同条款给我们一个直截了当的答复。

Stop ___playing ___games and give us a straight answer about the contract terms.