I provided three examples:

"Let's ordain women!"

This was rejected by the ordinary magisterium infallibly over a period of two millennia.

"Let's agree marriage is dissoluble!"

This was rejected by Jesus Christ Himself, Who amended the Mosaic Law.

"Let's approve same sex marriage!"

This is contrary to the Natural Law, and rejected by the ordinary magisterium over a period of two millennia.

Have a nice day.