It's really two questions. I think it's always helpful to work with a therapist when someone is not sure of their sexual orientation. The therapist might explore with the client, for instance, the nature of his or her sexual fantasies, especially masturbatory fantasies. After all, its the client who was making these fantasies up. As for the second question, people are complex, but it seems unlikely to me that abuse would change the sexual orientation.
Sexual orientation seems to be incredibly strong and fixed very early in life.
Yet, Mr. Young, there are many people who aren't sure of their sexual orientation until they get into a relationship and it becomes more settled in their minds. Unfortunately, all too many people, both men and women, get into a relationship early in life, perhaps have children, and discover in their 30's, 40's, or 50's that they had always wanted the sexual companionship and love of someone of their own sex. I don't know how to answer that. One of the standards which is often applied is that each partner is entitled to take out of the relationship in proportion to what he put in. Good evening Mr. Young.