When it is not appropriate to sing along I go over the words in my head.
Far too many people don't know there are additional verses. If they do know there are additional verses they have no clue what the words are.
"Ceterum censeo Hillary esse delendam."
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)
I have often, as well, ever since seeing this...
https://www.youtube.com/watch?v=I0fQd858cRc
It reminded me that I had learned this as a child and remember it yet. Have often thought it would be a wonderful surprise for someone to sing this stanza pre-game.