The hell is he taking out the code to explain it to customers? Are you sure he's "salsey"?
The only exceptions might be cases where very specific behaviors or implementation details are in question.
If they could build it themselves, they wouldn't be talking to us, but my co-founder doesn't seem to get this.
It reminds me of this Silicon Valley scene - https://www.youtube.com/watch?v=JlwwVuSUUfc
He may be showing people the code because he's proud of it...
Speak to him.