I have to assume you're just trolling. If that's the case, you really ought to find something more meaningful to do with your time. If you're not, you either need to stop taking drugs or start taking them.
Are you joking for real?
You asked for advice and I told what I think. Giving advice includes hearing where you suck too. If you want only to hear good stuff, next time ask for affirmation.
And what did I tell you wrong? Nothing.
Have you expect something special when intoducing potential wife to existing? There is no special sauce here.
And it's your job as man to push potential relationship forward. You are too risk rejection.
I have checked your posting. I haven't seen you said that you expressed your interest in her. You said she was interested in you and sad after she found you married. You said all interactions were friendly. So unless I missing something this is current situation from her perspective.
She was found potential mate. He is off limits due to marriage. And now this friend was invited me to short time together. Anyway, what are other men interested in me doing?
If you haven't expressed interest back, you are being timid.
If you haven't told her truth, something like: I believe that man can have multiple wives, and sadly current wife isn't fully on board. I think if I find good girl, she can be won. What do you think? You are being timid.
If you are wanting her and hiding that from her, you are being timid.
If you behave as friend and you want sexual relationship (which marriage is), you are being timid.
All you are communicating is you being fine with her seeking other suitors. She can't read your mind and, due to biological clock running out earlier, women are less willing to wait.
And you need to increase time together. Once a month is barely acquitance. People who seriously evaluate each other for relatioship, spend time at least weekly.