Isn't his problem - Idioms by The Free Dictionary
be not (one's) problem (redirected from isn't his problem)
be not (one's) problem
To not be one's responsibility, duty, or concern; to not be something one cares about or intends to be involved with. I know you're worried about paying back your loan, but your financial issues are simply not my problem—you're the one who decided to get into debt. A: "But sir, there's no way we can satisfy the requirement if my husband isn't allowed to work here in the first place!" B: "That's not my problem, ma'am. Those are the rules."
ˌit’s/ˌthat’s not ˈmy problem (spoken, informal) used to show that you do not care about somebody else’s difficulties: Well, I’m sorry you feel that way, but I’m afraid it’s not my problem.
References in periodicals archive
EASTENDERS A concerned Jean realises the time has come to take drastic action, but it seems Stacey only wants Bradley's help - and Syd is keen to make her realise that she isn't his problem