Q. How does one handle a parenthetical phrase within dialogue? For example, is this correct? “Hi, Tiger (his father’s nickname for him). What are you doing?”

A. Parentheses in speech or dialogue are awkward, because we don’t know whose words they are. If you really need to set off text in this way, square brackets [ ] are the standard way to set off an editorial insertion. But in a case like this, try rewording to avoid the interpolation.