Thankfully, I now no longer have to make sense of everything Hubbard wrote.
When I was an OT3 sup I assumed that if thetan A was stuck to thetan B, then the relationship was mutual, i.e. thetan B would also be stuck to thetan A. He did use the word "stuck". Doesn't being stuck imply a mutual stuckness? You can't stick a handle to a cup without the cup being stuck to the handle too. I agree there can be one-way obsessive attachments in life, with one person being besotted with ("stuck on"!) another who barely registers the existence of the first, but that is not really the same thing.
But now, what do I think about it? A waste of typing strokes.
Paul