Possible Clues:

• Cause annoyance
• Snipe eventually stuffed with grouse
• Get under the skin of
• "Pet" bone to pick
• Annoyance the day before exercising?
• 'Pet' grievance
• Bug always contracted after gym session
• Irritation exercises woman without parents
• Minor irritation
• Really freaking get to, as an annoying ghost haunting your boarding school might