1) Either realize that one night of pasta isn't going to kill you
or 2) Just let her know that you'd LOVE some meatballs but pasta isn't agreeing with you at the moment so you'll just have the meatballs and salad. That will still fill enough of your plate that it won't look like you're starving.
And maybe start the rumor for the future that you seem to be gluten intolerant and that you haven't found a grain that doesn't cause problems?
Zone diet on and off for several years....worked, but too much focus on exact meal composition
Primal since July 2010...skinniest I've ever been and the least stressed about food