it's (或 that's) someone's funeral

(informal)used to warn someone that an unwise act or decision is their responsibility

(非正式)［用于提醒某人须对本人的不智行动或决定自负责任］后果由…自负

‘I won't discuss it.’ ‘Don't then—&B{it's your funeral}.’.

“我不想谈这事。”“那就别谈——后果你自己负责。”。