I use to travel as CFX once o twice a month with AZA since the lasts 4 years
I usually introduce myself to the purser and sometimes he/she invite me to talk with the pilots, sometimes not
It ussually happens when flying on MD80's
I suppose it depends totally on the purser
I should say that most of the times i talked with the pilots, they invited me to sit in bussiness class
However i always travel without my uniform, and introduce myself as a "colleague", so there is the possibility (i suppose) that they think i'm a FA, so they consider not important to speak with the pilots