For this achievement you will need to have a Macaracoon fetch you a Romance Candy, first step, you will need to make him a resident by transforming him from a Sour Macaracoon (make sure the appropriate Tower of Sour piece is turned off if you have it)
-Level 24 Gardener
-Eaten 1 Cluckles
-Have 5 Master Romancer awards (7 of each type of species)
Once these requirements are met the Sour Macaracoon will go into a cocoon and then hatch into a regular Macaracoon.
Now when nightfall comes, hover over the Macaracoon and hit "X", there will be an option to make it fetch a romance candy, click it and it will run away for a short time and come back with a candy (may take a few tries as it doesn't always return with one), but once it does the achievement will pop.