This can be gotten about half-way through the Mini Golf Course on Day 2. This is easiest with 2 controllers
There will be a cinematic where one character is injured by a pig. After that, it explains how to ask for high-fives (healing) with
. Using 2 controllers, simply hold
with one character (they'll stick out their hand and sing). Avoid going near the other character while they're doing this. After 30 seconds, the achievement will pop.