XLIII that word

There are a lot of words that rhyme with duck,
But I can only really think of one,
So here goes, I'll say it, it is: muck.
Bet you were hoping for the other one.
Which is a rather puzzling expletive,
Because it can mean something that's so nice,
A noun, a verb, adverb, and adjective,
It gives to every life some added spice.
Were we rashly to yell aloud "Sex you!"
At people who annoyed us in our day,
They'd probably be cheered all through and through,
And have their outlook changed in every way.
   I don't know what to write down for this couplet,
   Perhaps it'd improve if I--destruct it.