The copy should be full of sensibility and love for the lover, and at the same time, some humorous elements can be added appropriately to attract people's attention.
You can express your love for your lover in the copy, for example, "Today is my love birthday, even if it is the only day in my life, I am willing.
At the same time, you can also add some humorous elements, such as "I don't know how many birthdays my wife has had, but I only know that she will never dislike my fat figure and unreasonable accent".
In short, copywriting needs to convey true feelings and let your lover feel your love and care.