Possible Clues:

• Jocular
• Playfully humorous
• Jocular desire to admit a horse, say
• Jokey
• Long to keep a horse? That's amusing!
• Said in a joking way, like dog's tail in motion?
• Witty, like Thackeray's snobbish author
• Facetious
• Want to be facetious about a horse?