Definition of that's your (or his, her, etc.) problem in US English:

that's your (or his, her, etc.) problem

phrase

  • (said with emphatic stress on pronoun) used to express one's lack of interest in or sympathy with the problems or misfortunes of another person.

    ‘he'd made a mistake but that was his problem’
    • ‘If you live overseas and can't figure out the time difference, that's your problem.’
    • ‘If you're getting fat from fast food, some politicians say that's your problem.’
    • ‘You think too much Mitch, I think that's your problem.’
    • ‘If you don't like my being friendly to others in this school, then that's your problem, not everyone else's.’
    • ‘If Mr Oaten failed to register his own names on the Web, then really that's his problem.’
    • ‘If he'd rather stay stuck in the past instead of moving on to the possibility of great new things with someone that he (seemed to) really click with, then that's his problem.’
    • ‘I mean seriously, if he doesn't understand your need for bigger (and not necessarily better) things then that's his problem.’
    • ‘How you cope with ordinary bookstores thereafter, well, that's your problem.’
    • ‘You're too sensitive, Christopher, that's your problem.’
    • ‘Yeah, sure, he doesn't have an 8 am class like you do, but that's his problem, not your flat mates’.’