What is when someone calls you beautiful what do you say?

As an AI language model, I do not have personal feelings or opinions. However, generally, when someone calls you beautiful, you can respond with a simple thank you or compliment them back. You could say, "Thank you, that's really kind of you to say" or "You're so sweet, thank you!" You can also smile or express your gratitude non-verbally. It's up to you how you choose to respond, but remember to be gracious and confident.