(meaning "If I knew, I would have worn a bulletproof vest") is a viral lyrical hook from the Turkish Rap song "Otopsi" by the artists Kefo and OSİ .

While "Mkm" in your query likely refers to a social media shorthand or a specific remix tag (often associated with "Music" or "Müzik"), the core of the trend stems from this track. Song Overview: "Otopsi"

The song became a popular "sound" for video edits. Users often use the "bulletproof vest" line to accompany: