Barbeque stopper, Australian slang, refers to a topic of constant and widespread conversation which is controversial and of contemporary significance. Such topic is likely to interrupt a barbeque with loud debate or discussion, thus called “barbeque stopper”.

Barbeque stopper（字面意思为“使烧烤活动中断的事情”）是一个澳大利亚俚语，指波及范围很广、对当下有深远影响且颇具争议性的话题讨论，即“热门话题”。烧烤的时候要是谈论到这样的话题，人们一般都会停下手中的烧烤热烈讨论起来，烧烤活动自然就会暂时停下来，由此得名“barbeque stopper”。

For example:

Sibling rivalry is the new barbecue stopper—at least in my circles.

手足反目是最新的热门话题，至少在我的圈子里是热门的。