In order to earn this trophy, you'll need to find all 40 Yaoi pictures of Tweak and Craig hidden around South Park. In order to collect them all, you will need to have all four of your special buddy skills. Spoiler warning: All four special powers are mentioned and shown in the video, so you have been warned if you don't want to see them in action!
This isn't a guide I created, but I followed this video in order to find the Yaoi pieces I still needed. Once I got the last one, the trophy popped!