告白的时候，用一些甜蜜的英文文案可以增添浪漫氛围，以下是一些可以用来表达你的情感的甜蜜英文告白文案：

1. You are the sweetest thing I have ever known, and Im so happy youre in my life.

2. Every moment with you is like a fairytale come true.

3. I love you more than words can say, more than time could ever take away.

4. You are the missing piece that completes my puzzle of life.

5. Youre the reason I wake up every morning with a smile on my face.

6. With you, I have found my paradise.

7. You are the sugar to my coffee, the cream to my cake, and the sparkle to my everyday.

8. You light up my world like no one else could, and I want to spend forever with you.

9. In your eyes, I see the stars, the moon, and the sun; everything that brightens my world.

10. Being with you is like having a never-ending joy ride.

11. You are not just a dream, but the reality that makes me feel complete.

12. You are the melody to my heart, the rhythm to my soul.

13. I could write a thousand words about how much I love you, but it still wouldnt be enough.

14. You are my today and all of my tomorrows.

15. Love is too small a word for what I feel for you.

记得，告白的时候非常重要的是真诚和情感的表达，无论是用简单的语言还是诗意的比喻，让他们感觉到你的心意是最重要的。