Sense and Sensibility by Jane Austen Chapter 12 Page 8

For such particulars, stated on such authority, Elinor could not withhold her credit; nor was she disposed to it, for the circumstance was in perfect unison with what she had heard and seen herself.

Margaret's sagacity was not always displayed in a way so satisfactory to her sister. When Mrs. Jennings attacked her one evening at the park, to give the name of the young man who was Elinor's particular favourite, which had been long a matter of great curiosity to her, Margaret answered by looking at her sister, and saying, “I must not tell, may I, Elinor?”

This of course made every body laugh; and Elinor tried to laugh too. But the effort was painful. She was convinced that Margaret had fixed on a person whose name she could not bear with composure to become a standing joke with Mrs. Jennings.