How about gifting your friend a personalized mystery book that features them and their spouse as the main characters? There are many book publishers that offer personalized books where you can customize the book's plot and characters to resemble the recipient and their partner. Alternatively, you could put together a "Mystery Movie Night" gift basket that includes some of your friend's favorite mystery movies, a bowl of popcorn, and a bottle of personalized champagne or wine as a celebratory touch.
Or you can get her/him a star map with the date of the wedding.
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.