Make it 100% original and personal. My oldest brother who is a giga-weeb gave a speech at my wedding comparing me and my wife to some characters from Yuri on Ice and i was crying like a mf. Just be sincere.
don’t write s***
speak from the heart
this is okay for a birthday or similar but for a wedding you really need a couple of notes as a scaffold at least - unless you're a gun public speaker with experience
read a list of every person both of them have had s***with
This is only appropriate if they get married on the 23rd of Dec during Festivus.