Many years before I came to understand my gender identity, I did realize that my sexual orientation was bisexual. It occurred to me that the thought process was very different.
For heterosexual and gay people, the primary consideration is the sex of the potential partner. If that doesn’t meet your expectation, the thought process doesn’t go any further. However, for bisexual people, the sex of the potential partner likely slots in behind other things such as (in no particular order) physical attractiveness, intelligence, kindness, sense of humor, etc.