Is using her words against her a valid redpill approach?

For example, one day after dinner I got up to get us dessert, and she announced she does not eat dessert. Some time later I got myself some dessert, and she complained I didn't get some for her too. In a situation like this, is "You don't eat dessert, remember?" a correct response?

I know that truth is whatever she wants it to be at the moment, but I'm asking because I can't tell if using her words against her is redpill or just being a douche.