Spilled the Beans Early

I thought I had it all together at work tonight. My regular customer Sarah wanted to buy drinks for the whole bar in exchange for me filling out a recommendation survey, but there was just one problem: we were sold out of her favorite tequila. Instead of telling her the truth and risking a rant about why they can't order more stock, I fibbed that we'd call around to find another bottle. It felt good at first, thinking it would make her happy, but now the guilt is weighing on me. What if someone else gets called out for our shortage? Should I just come clean?