I have feelings for my boyfriend's brother...

Jessie

I have been with this guy (James) for 5 months now and I have a came to the conclusion that I have very unresolved feelings. To put it bluntly I think I have feelings for his brother (Ryan). All three of us have a working relationship together and are all very good friends.
Ryan and I kissed long before my boyfriend and I were together and he admitted to me a long time ago that he liked me. Now no matter how hard I try to push certain thoughts to the back of my head it is impossible. Even though I don't intentionally think about Ryan in a lustful way I keep having these reoccuring dreams every night about me and him getting with one another.
We also have this love-hate relationship that effects us very much sometimes... we will begin childishly play fighting over very stupid minor things and it will escalate into a major fight where we spit out hurtful comments and then become very mad and hold a grudge. The other day this happened in front of my boyfriend and my friend told me that after I had left the room James told Ryan that he new we were attracted to one another and that is why we always push each others buttons... but he is not afraid because he knows we will never act on it.
I admit I am attracted to and have mixed feeling for Ryan, and I have strong reason to believe he feels the same way. This is not right... why do we have this strange attraction and what should I do about it...???