This is calling back to a song from chance the rapper’s 2019 debut album, The big day and particularly the song, hot shower.
These are the first main lyrics used by chance to convey to the listener. That he has muscles like Superman trainer. This means to the person who says this that he has muscles from the hero, Superman and also from a trainer, particularly an athletic one.
Usually a male but occasionally a female that derives sexual pleasure from encouraging an otherwise proper woman (often married) to act in an overtly sexual manner. This often begins with simple changes in her dress and proceeds over time to providing her with outlets for indiscriminate sex.
The slut trainer provides her with encouragement, opportunities, and materials. The preferred raw material is either a virgin or a previously faithful married woman (who becomes a slut-wife. He often becomes quite possessive of "his slut".