This achievement requires someone to choose an audience members lie in a game of Fibbage 3.
You can do this one of two ways, depending on what browser you're using:
Firefox:
Use the Multifox add-on for the Firefox browser. Install it and each new tab opened (ctrl+T) can be assigned a different profile by clicking the fox icon in the browser in the top right corner.
Google Chrome:
Click on the person image in the very top right of your browser. Go all the way down to "manage people" and click on it, then click on "add person" in the bottom right corner. Once you click it, click an image for them then click "save" in the bottom right corner. This will open a new pop up window for that person.
I'd suggest using the Firefox method as it's easier to navigate tabs than windows, but I couldn't get it to work for some reason so I wen't with Chrome.
Regardless of what method you use, open four tabs/windows and join a normal Fibbage 3 game. Have 3 of the 4 tabs/windows join in the game and start it, then have the fourth tab/window join as the audience. Pick a category and then, as the audience member, pick from one of the three answers that are provided. Make sure one of the other tabs/windows chooses it and you'll get your achievement.