When you send an email before you're ready to send.
You might hit send accidentally or your cat walks on the keyboard and sends it for you or the next thing you know, the email has been sent even though you haven't even touched the keyboard.
The prematurely send-jaculated mail definitely isn't ready to be sent as it might be halfway written, have a lot of typos, or be too rant-y or stupid to be sent, hence causing embarrassment when the email reaches the recipient.
Co-worker to another: I just hit the wrongkey and sent half an email to the boss that I shouldn't have!
Another: Premature send-jaculation is dangerous, hope you don't lose your job dude
Any sexual act between yourself, a coworker, and 2 voice actors. Usually following a video production.
Jim: Wow Alan, i cant believe we got famous voice actors Trey and Noah to appear on our show. This might be our only opportunity to perform an alabaster jackrabbit.
Alan: Thats a great idea! Ive heard about that, and we have to do it!
Trey: Thats the reason i got into this business.
Noah: Ive always got time for an alabaster jackrabbit, but let me stretch first.