Just like a regular secratary only one you have sex with instead of your spouse or current significant other. So, it fitting in the terms of s"extra"tary.
The whole office was buzzing with the latest news:

Morgyn: "Did you hear about, Jim?"
Keegan: "No, what happened?"
Morgyn: "Jim's wife came to bring him lunch and walked into his office to find him having a nooner with his sextratary right on his desk."
Keegan: "Sucks to be him."
by Saggysocks September 19, 2007
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