What Japanese couples usually say... sweet words... need to be written and pronounced...

I love you more than anyone in the world

private world の何でもより1人はallあなたを爱しなければいけなく

wa da xi wa sei gai no nan de mo yo li hi do li wa zan bu a na da o ai xi kai lei ba i gai na ku

It is too troublesome to just say a i xi de lu (I love You)

I’m afraid you won’t be able to pronounce it correctly if you read it in pinyin.