성배 (seong-bae) literally means "Holy Grail" or "chalice". This is a highly unusual and poetic word to find in a pop song, making it very memorable.
In "Blood Sweat & Tears", BTS sings "알면서도 삼켜버린 독이 든 성배" (a poisoned chalice that I drank knowingly). This powerful metaphor represents a love that is as irresistible and sacred as the Holy Grail, but also knowingly destructive and toxic. It's a perfect example of the deep, literary lyrics that make this song a classic.
South Korean boy group BTS lean completely into toxic temptation here, and they do not hold anything back. Right from the opening hook, they offer up everything: "내 피 땀 눈물" (my blood, sweat, and tears) alongside "내 마지막 춤을" (my last dance) and "내 차가운 숨" (my cold breath). The lyrics describe an obsession that feels dangerous on purpose. They compare this lover to "목 깊숙이 너란 위스키" (the whiskey that is you, deep down my throat) and even "독이 든 성배" (a poisoned chalice). It is dramatic, slightly wild, and totally self-destructive. You can hear them willingly walk into danger because the rush is simply too sweet.
Notice how the tone bounces between sugary metaphors like "Peaches and cream" or "Chocolate cheeks" and darker, trap-door imagery like "너란 감옥에 중독돼 깊이" (deeply addicted to the prison that is you). They literally ask to be tied up with "아파도 돼 날 묶어줘" (it can hurt, tie me up) so they cannot run away. Instead of fighting the trap, they surrender to it entirely. It turns the classic pop theme of a crush into a dark fantasy about losing total control over your own body, mind, and soul.