The phrase “Partner in crime” can typically be define in 2 with different meanings.
One, is literally a criminal who helps other criminals to plan and execute acts like robbing a shore or a bank together as a team with different roles.
Other meaning is used, when you and someone who you trust and he/she feels the same way about. The two of you usually get in trouble/spend time together, share secrets and other things with each other.
You can call someone a “Partner in crime” when you are in relationship with them or have feelings for each other, or are best friends, who are like brothers, so it’s like a relationship where both of you has the others back all the time and always.
The exact origin of the term is unknown unfortunately, but it is safe to say it is as old as it gets, as it has been around pre internet times.
The phrase is old enough for everybody to know it, so it is used all around the world.
Originally the phrase was only used by criminals, when they were talking about their partners.
Since its meaning and simplicity, the phrase is used daily, both in person and on the internet.
The phrase is mostly used on message board websites like 4chan.org and Reddit or personal blogs all over the internet.
- Urban Dictionary – Partner in crime