(CNN) Even professional athletes have to keep their parents cool.

Coco Gauff's dad, Corey, was wearing a microphone at the Auckland Open when he let the word "damn" slip as he was coaching her up courtside.

The 15-year-old American tennis star let him go on for a second before she corrected him.

"You can't curse," she said, holding back a laugh.

"Did I curse? I said no, it was real weak..." Corey responded.

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