Trey does not refer to anyone as a friend.
When approached by Cater about taking a picture with a melon that is “supposed to make friendships last forever,” Trey refuses.
Cater refers to Trey as his best friend and Trey does not deny it (in the original game).
This is one of only four times that the word “best friend” (親友) appears in the original game.
Chenya refers to Trey and Riddle as childhood friends but Deuce says they do not seem like it, which is a sentiment repeated by Ace.
Twisted Wonderland Reference Note 