Mr Samuel said Ms Akhtar had emailed Mr Greenstein telling him to “stop picking and choosing, stop behaving like a Muslim, it’s embarrassing".
On another occasion Ms Akhtar, 28, allegedly responded to an email about throwing wet sponges at her by writing: “Typical Jewish behaviour, always first in line to hit a Muslim.”
Mr Samuel told the tribunal that this and other emails were part of an easy relationship where both could “joke confidently and know that people wouldn't be offended".
The case continues.