wow, intense discussion here.
id just like to add a few things to the incest debate.
firstly a question, whats the official stance on the fact that if Adam&Eve ever existed, to create the world there would have had to have been incestuous relationships.
but anyway.
incest is taboo. in certain places it is not still taboo, people marrying cousins etc.
and there have been some very sad stories recently about adoptive siblings falling in love, or one awful case of a father being a sperm donor, and two of his 'donations' later falling in love without knowing. they had a child together. they were in love.
i do not agree with incest, i think that to actually become aroused you have to have a strange relationship with family members, ditto child abuse.
they are both wrong.
however, erotic fiction is just fiction. maybe the fiction is good on the action and the incest is sidelined [having come across such a story on literotica and, it having a neutral title, not realising the nature of it.] some of these stories, especially on sites like these, only add in the incest stuff later so that their stories can climb the toplists, as that is what is popular. the one i saw literally went a page before mentioning the incest.
im not condoning it, just offering some new arguments.
if i found out my DH occassionally had fantasies about men, for example i wouldnt doubt his sexuality or our relationship. if i found he had accessed a gay porn site, i would sit down with him in a non-judgemental state and find out whether it was pure curiosity or a deeper motive.
[maybe this is because i am of the school that sexuality is an ever moving target and than your particular favoured gender may not do it sometimes]
OP, have a chat with your DH without being confrontational or judgey, because he will leap up to defend himself and he wont be honest about what he is feeling.