It has little practical possibility of becoming a reality, and you aren’t really pursuing what practical possibility it does have (i.e., in the MMF threesomes that are difficult to set up and underwhelming to you, at any rate). In the realm of thoughts and fantasies, your interest in gay male sex is benign.

When they become problems is when they manifest as potential harm to others, like in the case of someone determined to act out their abusive fantasies. Desires and fantasies are, for many of us, largely out of our control and, in their raw, immaterial form, innocuous. There is nothing positive about shaming a client for her desires, no matter how they deviate from the generic script of pro-social conduct pushed by supposedly well-intentioned people. It is chilling that someone who behaved that way has ostensibly devoted her life to service.

The scare quotes around “sex-positive” to describe that therapist are apt.