If a Leo man has a crush

How can a woman tell if a Leo man has a crush on her. I feel a unexplainable vibe when we are close, I think I see something in his eyes, and often wonder if he sees and feels the same way I do.
I am a Pisces and I have been reading up and we are not sopossed to be a very good match.
Are Leo's pretty blunt, he has often told me how big of a crush he had on me in high school.
Ok wait there is a catch, I am in a relationship and so is he.
I can't quit thinking about him. I am starting to think its the "whole want somehthing you can't have type of thing"

I wish it was that easy. What a terrible thing ya know. Its a shame, is what it is.
That is one thing I don't like about being a Pisces is i am alway daydreaming. I try really hard to see things as they are, but its hard.
I love the cancer man I am with, I have been with him for 14 years (i am only 26).
We share the same goals, and morals, and we work together at home as "home team".
But sometimes I wonder have I found my soal mate ( there I go thinking again) WOW!
This Leo man reminds me of my father alot, in ways like he is a very hard worker, and he likes to fish, (my cancer gets seasick), hunt, and do things. And so do I, my cancer man likes to stay home and save money, which is good, it really is. But I just wish he liked the ocean, and nautical things as much as I do.
Maybe I will meet him (my soal mate) in my after life. Maybe this is a test for this lifetime.

Thank you Dancing Bread for your much needed response.