The Buzz Radar on Instagram: "That moment when Christina Aguilera surprised fans inside a random donut shop with an impromptu mini concert was pure joy. Hidden cameras were rolling as she sang parodies of her biggest hits “Genie in a Bottle,” “Lady Marmalade,” and more using the customers’ outfits and orders as lyrics. No one had a clue it was her behind the counter until she stepped out and handed them donuts herself. Their reactions? Absolute shock, disbelief, and pure happiness. This wasn’t a