Help ME!!!

Its been a years since Ive read this but Ill do my best to summarize and hopefully someone may know it.

In point form.
- Two brothers (I think they were twins)
- They come from a broken home.
- Mom remarries and they get a step-dad
- One brother is happy and welcoming while the other is distant
- One of the brother fell in love with his brother
- The other brother does not know or did not feel the same, Im not sure.
- The Stepdad wanted to get closer to the distant brother to create a happy family
- They went out on a "bonding date" (an innocent bonding time)
- Then the brother lied and confess to the step dad about being distant and the reason for his behavior was that he liked him.
- They started having sex.
- The brother who confessed is using the step dad as a replacement for his twin.
- He can only get turn on by thinking about him while he is doing it with the step dad.