How about getting him a new model rocket kit to build together? You can bond while building the rocket and then have fun launching it together. You could also consider getting him a new rocket engine or some of the accessories like launch pads, igniters, or parachutes. Additionally, you could buy him a book about model rocketry or a subscription to a rocketry magazine to help him expand his knowledge on the subject.
Or you can get him a star map with the date of your first kiss.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.