Reccuring dreams about my brother

A recurring theme in some of my dreams is one of my older brother wanting to have sex with me. This would never happen in RL and even the idea of it disgusts me--not only for the incest issue but also because he is unhygienic and sloppy.

I just had the latest version of this dream this morning and I was so weirded out that I couldn't even stand to have my husband touch me.

I really like to figure out what is going on and if I can get this theme to stop.