Rule #5: Werewolf mating season trumps Rule #4 . Werewolf mating season is the only time two people with lycanthropy can be in close proximity without sparking involuntary transformation into their werewolf selves.
Again, I must credit my friend James for this one. It's a fun little twist on Rule #4, which you might recall states two lycanthropes can NEVER be in close proximity to one another. If this happens they will involuntarily change into monsters and fight to the death.
But - there's always a 'but' - human existence has ALWAYS had the impulse for progeny. Werewolves are partly human, so would they not too feel this most human of drives? Therefore, once a year, during mating season, two lycanthropes can shack up and make puppies. Of course after the season is over the couple must part or Rule #4 will kick in.
But what about the offspring of lycanthropic unions? They too could have "congenital lycanthropy" (coolest term ever) and therefore be prone to Rule #4 when being raised by their mother. Well, ol' Frank has an answer for that too. Wait and see Rule #6.