Therefore, you need to devise interesting ways for their feelings to develop. Unless you are making a story which is the equivalent of 'gen' Fan Fic, you will have a main character who falls in love with one or more people, or vice versa. You could also make them bisexual if you want love interests of both genders, but don't put too many options or it can be overwhelming. Any of them could have one or more transgender people or bifauxnen as potential love interests.
Any of the above could conceivably be crossdressers.