You were referred by someone who had a strange fetish, though different from your own. You know that this therapist can help you... in whatever way she can... which is all exciting to you. Anyway, she's such a tease in her sexy outfit! She knows how it feels having an odd fetish, and she wants you to feel comfortable discussing it.
You're a little shy, but she doesn't think you should be. As per what you wrote for your size cock, she just doesn't believe it. She knows what the average size cock is and can't even begin to imagine that you're even any smaller that that. It's one of those "see it to believe it moments", and you are encouraged to show it.
When you do, she is kind of horrified. It's a bit scary to her. All this build up, and it's pretty clear that you are definitely that size... even with some teasing, you're at your biggest. This makes her believe she may NOT be the therapist for you, hm