IFLY
If you go out to dinner with friends and talk about flying the whole time you are talking shop.
If you discuss technical stuff on the flight deck while at work you are simply improving your professional knowledge - just go ahead and do it, but as a discussion not as a test of your co-pilot! I learned tons of useful stuff from co-pilots.....
Definition of a Pilot..
When he is with another pilot he talks about girls...
When he is with a girl he talks about aeroplanes...