I once asked her what she identified as. She proceeded to tell me that while she identified as pansexual, she chose to tell people she was bisexual. At the time, this was a little tough for me to understand. However, over time, I began to understand why she did it.
When you - a straight person - visit a therapist, they won’t assume that all your problems stem from your sexuality. They are not going to confront you saying that “That bi thing you’re doing” is wrong and that you should stop being bi.
A majority of people are always interested in “that Pride Parade” but very rarely would they have a completely normal reaction to you being in any kind of relationship that is not a monogamous, heterosexual one; the only kind society completely accepts.