Possible Clues:

• __ out (unsubscribe)
• __ out (decline to participate)
• Decide to join, with 'in'
• Reach a decision
• Plump and old, needing exercise?
• Choice word?
• Obsessed pie taster starts getting plump
• Show favor (for)
• __ out (don't participate)
• Accept, with 'in'