The phrase comes from French slang, where sur mes morts is a strong way of insisting that something is true, and mama adds a personal, emotional edge that makes the line feel even more intense. As a clip, it has circulated through meme and short-video culture, where creators lift short, quotable vocal moments and reuse them as reactions rather than dialogue. Its brevity is part of the appeal: it can be dropped into any edit without explaining the context, and listeners familiar with French internet slang recognise the attitude, which keeps it useful for dramatic, ironic and playful moments alike.