Toxick
Splat
It was a joke, let me set it up.
Child dies far away from home at 2am fighting over mcnugget dipping sauce.
Reasonable question is asked, "why were they in DC at 2am"
Perfect joke, "Obviously, because the Waldorf McDonald's closes at 11pm".
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It's funny, because obviously that was not the intent of the question (why are your kids running around unsupervised late at night).
As a general rule of thumb I say that if you have to explain a joke it wasn't funny.
However, I did get the original joke, and I thought it was funny.
And ironically - the explanation is funnier.
Irony is funny.
Usually.