Insider asked current and former Starbucks baristas what annoys them the most on the job. They shared five customer pet peeves, including not cleaning up your cups or utensils. "Love red-cup season," Tayla, a former Starbucks barista who's based in the UK, told Insider. Insider spoke with three current and former Starbucks baristas about their biggest customer pet peeves, and what customers can do to make the holiday season more cheerful. "I did love working at Starbucks," Tayla said.

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