Kiya, I like your sticker idea!
My father chose not to want a relationship with me until I became an adult. (parents divorced when I was 4) I don't mind getting him a card. It's just hard to find one that doesn't say stuff like "What a wonder father you've been".

You must not lose faith in humanity.
Humanity is an ocean;
if a few drops of the ocean are dirty,
the ocean does not become dirty.
~Mahatma Gandhi~