Trash Talking is a Free Action

Each round takes six seconds. This does not mean every turn takes six seconds, but really that all turns share the same six seconds.  So at a table of four facing two enemies everyone has a single second to call their own. But as people are delaying and acting in succession, so it might easily be less. A lengthy fight in D&D might last two or three minutes in the world but an hour or two at the table.

And if someone hesitates their second can last entire minutes. The entire world holds its breath until that one person acts or delays.