Ah that’s a deep question haha. But in reality if i happened to run into them casually. I think i would tell them the truth about my feelings back then.

"Masih hidup lu? Perasaan dulu bilangnya ga bisa hidup tanpa gw"

Frankly honest, I don't know what to say since I'm not talking that much. But, I might ask about how life has been so far, is there an unforgettable story you'd like to share? Anything like that. Rather than thinking of our past, I'd love to know them as who they are right now.

You've got to eat clean and live longer. You were an ex that turned out a great bestfriend to me, and I haven't told you that yet. But thank you, at least you said your farewell very politely by having us talk and give closure to each other. Missing you lots, still am sad to know you're gone forever, but happy belated birthday, best bud.

mau sampein maaf karna sifat dan perkataan aku waktu itu. aku menyesal dan ngerasa bersalah banget karna hal itu. mungkin dia gaakan maafin, tapi aku akan sangat lega karna berhasil nyampein rasa bersalahku

I'd just say "Hi, how's life? Hope it treats you right..."

Aku.. belum pernah nemu orang yang aku sayaaaaang banget dan pisah sebenernya jadi, nggak tau juga gimana rasanya. Tapi kalo misalnya gitu, aku bakal bilang ke mereka, i'm glad to met them in that time, larena mereka aku jadi pernah merasa bahagia yang sesungguhnya, bisa nggak kita hidup lagi bareng-bareng?