My mom was like that sometimes. Not about Santa, but she'd be like "Okay, so you're in elementary school now. Kids are going to start to use the bad words they learned from their big brothers and sisters, but don't you use them, okay? So, if you hear words like 'bitch' or 'shit' or 'asshole' or 'fuck'.." and she'd keep going lol. She wanted to make sure she was the one who taught me the bad words.