Check out Dr. Robert Epstein's work. In exploring sexual orientation, he surveyed a large sample of men & women & found that sexual orientation was on the same sort of continuum we see for many measures. He found that very few people were strictly hetrosexual or strictly homosexual, but fell somewhere 0% to 100% either or. Where people fell on that spectrum impacted what types of relationships they were comfortable with. Someone 80% heterosexual could be happy going their entire life in only straight relationships, while someone 30% heterosexual - i.e. 70% homosexual, might have sex with the opposite sex but would probably be more comfortable in a homosexual relationship. It depends on degree & other factors, including one's family & society's attitudes. 

On the other hand, when he measured gender characteristics he found that most adults are right in the middle with a mix of both feminine & masculine traits. Hyper-either gender was rare - but those outliers might explain dysphoria.