I promise you
You say this when you're in love so hard it feels like your heart's going to explode and you're also too scared to let them go.
'I promise you, I'll never forget you!' said the kid who forgot their own name.
'I promise you, I'll always be there for you!' said the kid who was never there for anyone.
'I promise you, I'll never leave you!' said the kid who left right after.