word origin

The reason doesn’t actually involve dogs and cats.
One origin story for f*ck is that it comes from when sex was outlawed unless it was permitted explicitly by the king, so people who were legally banging had Fornication Under Consent of the King on their doors, or: F.U.C.K. But obviously that's wrong. And if you do believe that, stop it. Stop it right now.
If you think 'totes', 'fangirl', and 'trick out' are recent idioms, then I'm here to surprise you.
It crops up in our speech dozens of times every day, although it apparently means little. So how did the word "OK" conquer