The Little Mix singer was sitting with friends at the restaurant, when they were approached by a man who started abusing the star before slapping her in the face, reported Femalefirst.
"He kept saying, 'if my girlfriend was here, you would both feel really intimidated. And then he said something like 'shut up' to Leigh-Anne's friend," a source said.
"Leigh-Anne turned around and said, 'don't say that to her' or 'don't be rude.' And he walked around the table and leant into her and gave her a clean slap on the face."
"He was really aggressive. He seemed like he had been drinking. She was laughing about it at first but then she completely broke down, crying. Her friend was comforting her," the source added.
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