Werewolfs

Okay, I'm beginning to get annoyed cuz my Sim won't turn into a werewolf. I did what everyone's been telling me to do, which is to become friends with the black dog that has glowing eyes (I know the dog has a good relationship with my sim cuz I did a cheat and put it at 100). The dog and my sim are now friends and it said that i have to stroke the dog, which I did. He's supposed to nibble my sim, but he NEVER DOES!!! It's really annoying. Am I doing something wrong? What do I have to do to make my sim a werewolf?

PLEASE HELP!! I'd really appreciate it!

(And 'yes' I did post this message twice. One on here(pets) and one on the regular sims 2 message board)