Despite what people might think, our body parts don’t actually have much to do with our gender. So regardless of what’s happening in someone’s pants, straight people are still straight—even if their partners are trans.
First, some biology. One of the major reasons that people tend to think that all transgender folks are gay is the idea that sex and gender are the same thing. And that your sex, or your sexual organs as they appear on your body, are what determine your gender.
“Gender can be conceptualized as an inherent or a deep sense of self regardless of our body parts,” says Dr. Reece Malone, a sexologist and sex therapist. “I often talk about how people can lose a limb due to illness or injury, however, that doesn't change their gender identity. In other words, if a man loses his prostate due to cancer, it doesn't make him less of a man. We're still our gender regardless of the body parts we have or don't have.”