Epel says that his preconceived notion of Clock Town involved it being “graffiti all over the place,” and Deuce mentions experience painting walls with spray paint during the Rapunzel event.
When asked if he has done such a thing before Deuce responds, “Yeah, I’d use spray paint to—Wait, no!,” and claims his experience comes from painting roses at Heartslabyul.
Jack observes, “I don’t have to read that far between the lines to guess he was probably up to no good.”
Kalim says that Deuce recommended a certain type of spray paint to him.
Ace is not one of the people that Deuce has confided in about his past but he has been calling Deuce out on his 不良-speech since the prologue, as the his vocabulary is often yankee-coded (referring to Riddle as カシラ both to his face and behind his back (EN-server: boss / top dog), to Heartslabyul as his “turf,” etc).
※Note: While “boss” is a perfectly accurate translation of kashira, it might not be having the same effect on EN, as EN will add the word “boss” to places it was never said (re: Ruggie to Leona, the twins to Azul) but Deuce is the only character in the game to use the word “kashira,” which is why it stands out and why Ace calls him out on it but not any of the other characters who also say “boss” on EN: it is supposed to be unique to Deuce’s speech patterns.
Deuce mentions riding a magical wheel before enrolling at NRC, and he discusses blastcycle modifications with Epel that are very reminiscent of the yankee motorcycle aesthetic.