Out of the groups I stan, I can call four of them oppa (EXO’s Xiumin, then BtoB’s Eunkwang, Minhyuk and Changsub)
Changsub is only a day older than me, but a few other members are born in 1991, but after my own birthday. Girlgroup wise I can call none of them unnie, though Chorong is only a few...