SS5o1(Triple S) - Because 1’m Stupid (B0ys 0ver F1owers OST) Sub’d (Open Concert)

SS501(Triple S) - Because I’m Stupid (Boys Over Flowers OST) Pronounced Double S 501. Usually consists of 5 members, but because 1 member is busy shooting BOF 1 member is busy performing in a Grease musical, a sub group called Triple S consisting of 3 members was formed until the other 2 members rejoin