You and I, both, need to protect our own interests. A provisional patent is very helpful but an NDA (non-disclosure agreement) and confidentiality contract is very important to both for our successes.
I am offering this printable download of a contract to put-into-writing our mutual understanding.
Just print it, read it carefully, and if you agree, sign it, scan it and send it to me via email. You can mail it if you prefer. I do not use a fax (too sloppy).
You may want your legal counsel to peruse the agreement.
I also offer, as a download, an example of what a licensing agreement contains.