Related Clues:

• Show you're human
• Foul (up)
• It may be done on the side of caution
• Prove one's humanity?
• Prove to be human?
• Martini option
• Need to be set straight
• Mess up
• Blow one's lines
• "To ___ is human"
• O. Henry story feature
• Botch things
• Bobble a grounder, say
• O. Henry plot specialty
• Commit a faux pas