That means you'll have double happiness.

那就说明你会双喜临门呗。

youdao

Friend, can double happiness, the sadness in half.

朋友，可以把快乐加倍，把悲伤减半。

youdao

To give happiness to others, equal to the double happiness.

把幸福让给别人，等于得到了双倍的幸福。

youdao

In the nineteen-eighties, a carton of Double Happiness cigarettes was enough to secure a job transfer or the ration coupon for a washing machine.

NEWYORKER: Boss Rail

Companies produce and sell more than 400 cigarette brands in the country, ranging from the high-end Zhonghua and Double Happiness to cheaper brands like Little Panda and Yellow Pagoda.

CNN: China clouded in cigarette smoke