I have a hard time seeing how being in this scenario is therapeutic or healthy. And even if the client takes this feeling to another therapist, I can't see how that is necessarily going to help, other than just having someone to vent to. In my case, doing self therapy, reflection also led nowhere. People have needs. Therapy provokes those needs better than just about anything else. Logically, perhaps it is better not to provoke deep needs if they are going to be frustrated by design. It's pretty cruel.

I relate to the OP's predicament. Therapy can feel like you are having an actual intimate relationship. This naturally triggers feelings of jealousy. And then the client made to feel guilty or weird about this, as if they brought it about.

My experience was that having such intimacy with a therapist led directly to the intense feelings. And then there was crushing heartbreak, crushing frustration, crushing jealously, and crushing obsession.

Of course my own personal history had much to do with it, but still the feelings were a product of therapy!