Sorry didn't really grasp the depth of the anxiety problem. I was just thinking in terms of being or soon to be married life partners and not being able to share these type of things when the topics been broached more than once prior and clearly such things are not going to be judged as taboo or out of bounds.
How about say ...remember that time you mentioned our good friends and asked if would I like that type relationship ....I think I'd like to talk about that concept and possibility of something like that. (see boat still there... you got another chance)
How about writing a note saying you posted some thoughts and comments on a forum and would like his input on the thread and send him a link to this thread. He knows of you struggle with anxiety right???....this could be a strategy for broaching difficult topics. Maybe talk to your therapist on effective methods to start difficult conversations. Write a journal ...then ask him to read it ...