Wow, I wouldn't answer that question at all, I would consider it a major red flag and do some questioning of my own....
(incidentally, I'd never invite a chick to coffee, but that's another story)
ME: Coffee, perchance?
HER: Is this a "friendly coffee?"
ME: What exactly do you mean by that?
Chances are I would 'next' her based upon that question alone. However, I would drill her and drill her as to what she means by it first to make sure.
As someone stated above, that's a question which is really a statement. The statement is: "I would rather f*ck my little brother than f*ck you."
Why would you go out with a girl who made that statement to you? Start doing some screening of your own FFS.
EDIT:
Just read this...
update...kind of anticlimactic, but I decided to take TillTheEndOfTime's advice this morning when I realized that I wasn't really too excited to see this girl. Why? I can tell when a girl's not interested. Trying to get a date out of her was me grabbing at a straw after two bad dates last week.
Thank you for coming to your senses.
Only the worst AFCs go out with women
after being friend-zoned.