Related Clues:

• Sensitive area
• Sensitive topic
• Vulnerable area
• Touchy subject
• The "there" in "Don't go there"
• Grudge, perhaps
• Conversational taboo
• Subject best avoided
• Subject to avoid
• Touchy matter
• Poisoner let loose before time, providing grievance
• Annoying issue
• The "it" in "I don't want to talk about it"
• Bad options are hiding a vexing subject
• Touchy subject: bruise, perhaps