Aaargh. This brings up memories.
I just shed a few tears for the dog that was with me until my 13th.
Last weekend a cat from the uncle of my girlfriend was put to sleep.
She was really old for a farm cat (9 or something).... my girl and her mother had a really strong relation with her, even though she wasn't their cat.
It felt so bad to see my girl crying for the first time.
I'm sorry to hear that BF. It really was a special cat.