So far, Stevens has never spoken, only occasionally making noises. He seems to not belong to any cliques or social groups, seeming as though he prefers to be a loner. Stevens seems to bring his instrument wherever he goes, so that whenever something unfortunate happens to other students, he plays the "Sad Trombone" melody, much to their dismay. A lot of people are annoyed by this constant melody, the Band Instructor telling him to cool it, Randy complaining how unnecessary it was for him to play it three times, and stanked Juggo getting revenge on him for playing it every time he dropped a juggling pin.
In "Randy Cunningham and the Sorcerer's Key", it's revealed that Stevens is a tomcat, giving band pins to all the girls he likes, not just one. This often gets him in trouble with Flute Girl, who gets stanked (and fused with him) in said episode because she feels betrayed and in "True Bromance" because she's jealous of him doing stuff with other girls.
Stevens hangs out with Flute Girl on many occasions, and seems to like her quite a bit, although he doesn't appear to be as interested in her as she is with him. They eat cotton candy together at the Bash Splash in "House of 1,000 Boogers". They make memories during Julian's birthday party and sit together to watch Knightfire's show in "Julian's Birthday Surprise". They raise a baby together in "M-M-M-my Bologna", and they win the Best Buds competition as a team in "Best Buds". Because of Stevens' tomcat behavior, Stevens often has to deal with Flute Girl easily getting upset at him and becoming stanked, which can put himself and the other girls in danger. For example, when Stevens gave a trombone lesson to Rachel, Flute Girl was furious and went after them as a monster in "True Bromance".