Because of my work as a novelist, editor, and book reviewer, I come across a lot of poor representations of bisexuality and bisexual people. I write primarily for a bisexual audience, so I'm conscious of how our community is seen in media aimed at non-bisexual consumers--for example, readers of M/M (male/male) fiction.
Because bisexual people have shown ourselves to be somewhat of an untapped market, many authors are now reaching out and giving us what we've longed for. Some do this very well; I have a few colleagues who write excellent bisexual women, and I've discovered several non-binary trans authors who write outstanding bisexual characters of various genders. Others, however, are not doing so well at understanding us or our community. This is often something I see from authors who are either not bi-identified or who are but primarily spend their time in gay and lesbian spaces. They tend to make a number of painful errors: avoiding the word even if they "show" the character to be bi (that's a whole separate discussion); having a bi-identified character become "really just gay"; continuing to use phrasing which implies bisexuality is not in and of itself a stable identity.
My current pet hate is for the phrase "gay side." Some examples of how I've seen it phrased:
- exploring their gay side
- hiding their gay side
- discovering their gay side
Absolutely no one ever suggests that a bisexual character previously in a same-gender relationship who falls in love with someone of a different gender is "exploring their straight side." No one suggests that a bisexual character in a same-gender relationship is "hiding their straight side." Hiding one's bisexual identity--either in the straight or gay community--is simply called "being in the closet." Full stop.
Presenting someone in a story as having a "gay side" does a disservice to the bisexual community. It perpetuates myths such as bisexuality being an unstable state which will settle down as soon as a person has a partner or that it's merely being confused or experimenting. It implies that if a person continues to identify as bisexual, they will one day decide to "go straight" and leave a same-sex partner. It also implies a person who has mostly been in different-gender relationships has done so in order to hold onto straight privilege and avoid being labeled "queer" rather than because that was who the person was in love with at the time. All of those are rooted in ignorance and biphobia.
In M/M fiction, the goal is to have two male main characters end up in a relationship together. This does not need to be done at the expense of the bisexual identity. It only requires the writer to have a broader understanding of what it means to be bisexual and how a person's bisexuality informs their relationships. It's not necessary to be bisexual to write good bi characters, but it definitely helps to know a few of us (and have us be your beta/pre-readers).