How to skillfully ask your girlfriend's birthday without trace?

Do it with your heart, as long as you want it, your heart will succeed. Actually, if I were you, I would just ask her what her birthday is, and then I wouldn't mention it. On her birthday, you appeared in front of her with flowers and gifts, and she asked you why. When you say that today is the baby's birthday, she will be very moved, because you can remember and prove your heart, and it is at the zero point of her birthday. ! ^_^