This might be a little confusing,
but it's between a boy and girl.
One saying they need the other,
and then they reply, "You promise?"
And then other says they love them,
and basically, one replies, "Always."
They are finishing each other's sentences. (:
Note: If you

this, please comment!
I prefer comments over a

(the word 'love' with letters being risen like that. It's distracting. Your 'need' and 'always' being bolded and italicized is fitting though. )
I loved the "Always." <333
Love the effect of finishing each others sentences, very cute