Ok, my date got all mad because I ordered 5 items for 5 dollars at arbys and told her to buy her own, why?

I was freakin' hungry and it was our first date. I gave her a coupon for a free arby's melt but told her she would have to pay for it herself because I was out of cash. But I gave her a coupon for a free one, plus she was all pissy because she said arby's drive thru wasn't romantic, whatever. We made love later.