Michael R.E. Adams 
A Tete-A-Tete Among Wolves (A Seat of Gately Story) [EPUB ebook] 

Dymion Gately knows that only a life of sacrifice and mediocrity awaits. Adulthood can be such a dull ache. However, even the promise of boredom is threatened. His brother has undergone a startling change that could bring a childhood of love and devotion to an end. Everything now hinges on a supernatural secret.
The Seat of Gately employs Victorian flare and modernist depth to craft tales that are both lyrical and naughty. Complex characters commit to troublesome lies in order to fulfill their desires. Unfortunately, their greedy hearts and sad souls may be their undoing. They only turn into werewolves once a month, which leaves plenty of time to have very human problems.