Related Clues:

• Atomic Kitten's fond farewell
• Parting words, perhaps after the visit suggested by the starts of 20-, 38-/40- and 54-Across
• "That's it for me!"
• 'I gotta run!'
• "Peace out"
• 'Peace out, suckas!' [drops mic and exits stage left]
• "I gotta run!"
• ''Ciao, baby!''
• 'Buh-bye!'
• Casual parting ... and a hint to this puzzle's four longest answers
• 'Ta-ta for now!'
• 'Hasta la vista'
• 'I'm off'
• Casual parting words
• 'I gotta split!'