Possible Clues:

• 'I don't care what they do'
• “Like I care what they do”
• "See if I care what they do!," informally
• 'Sure, they can go right ahead'
• 'Eh, they can do that'
• 'I don't give a darn what they do!'
• "I don't give a darn what they do!"
• 'They can go ahead, far as I'm concerned'
• Gershwin's '___ Eat Cake'