Translation
I've heard you're getting married today
I changed last night,
and you'd leave again.
Trust me, I can't, my mom would be mad*
at me if I loved again.
What was left of me was a memory.
What was left of you was a pain.
Just don't smile that beautifully.
I've heard you're getting married today,
don't I know?
I've heard you don't miss me,
don't I hear?
I've heard you're getting married today,
they say so.
You haven't been missing me,
they say so.
*His mom being mad has got to do with how hurt he was. His mother doesn't want him to be that hurt ever again. Here he is picturing how hurt he was with an innocent sentence like a kid, i can't my mom won't allow. Because he is ashamed of saying how hurt he was and therefore he can't dare to love again explicitly, he makes an excuse like a kid would