Possible Clues:

• Fun in bed?
• Hanky-panky (informal)
• Playful sexual activity
• Saucy play from which friends will return with delight
• Hanky-panky
• Sex
• Inept lads lack involvement in hanky-panky
• Naps killed cat, excited by amorous activity
• Reaper touring Santa's home disheartened, having little time for fun
• Rumpy-pumpy