Hi,
I've no idea who or where you are, but I thought I'd make three comments: (1) Congratulations on your good relationship -- may it continue and grow even better. (2) Your friend is perfectly right about the word "anniversary": it literally means the "turn of a year", so you shouldn't even say something like "ten-year anniversary", since "year" is redundant -- you should say "tenth anniversary". (3) Your friend is a poor philosopher: the fact that rights are a "human construction" doesn't say anything about to whom or what the concept may be applied. Have him read The Case for Animal Rights, by Tom Regan.