My boyfriend insists that commas and other forms of punctuation should be outside parantheses. I insist that this is (of course) completely and egregiously incorrect in American usage.
We told her the truth, but she didn’t pay attention (of course.)
vs.
We told her the truth, but she didn’t pay attention (of course).
Your boyfriend is essentially correct (surprising though it may be). (But, if you start a sentence inside parentheses, the period ending said sentence goes inside the parentheses.)
Commas should never occur right before the opening parenthesis. We told her the truth (the silly fool!), but she didn’t pay attention.
You’re confusing the British vs American usage of quotation marks or, as they call 'em across the pond, “inverted commas.” This rule does not apply to parentheses. The only exception is as Hilarity stated.
As I said, I am no authority, thank for clearing that up a bit Hilarity, it makes a lot more sense the way you decribe it. Of course I will probably keep doing it wrong forever! Some cases of ignorance are hard to let go of and I guess I am one of them. That is why when I publish my book I will hire a good editor. Thanks for the advice.
From Wikipedia:
In both countries, the “British” style is used for quotation around parentheses, so both nations would write:
I am going to the store. (I hope it is still open.)
But:
I am going to the store (if it is still open).
From Blue Book:
Rule 3. Periods go inside parentheses only if an entire sentence is inside the parentheses.
Examples Please read the analysis (I enclosed it as Attachment A.).
OR
Please read the analysis. (I enclosed it as Attachment A.)
OR
Please read the analysis (Attachment A).