consent
Explanation
In this comic, a woman with green-tinted skin says nervously: "I just... it feels like I shouldn't." A silhouetted figure (Superman) responds enthusiastically: "I give you my consent! I'm into it! I'm working through my childhood! The safe word is Metropolis!"
The caption reads: "The worst thing about dating Superman was the kryptonite fetish."
The joke plays on the well-known Superman mythology. Kryptonite is the radioactive mineral from Superman's home planet Krypton that weakens and can kill him. The woman's green-tinted skin suggests she is either holding kryptonite or has been exposed to it.
The humor works on multiple levels. First, it imagines Superman as having a fetish for the one thing that can hurt him -- kryptonite exposure -- which is presented as a form of masochism. His over-enthusiastic consent and mention of a safe word frame this as a BDSM scenario. Second, the woman's discomfort ("it feels like I shouldn't") creates an ironic reversal: normally, kryptonite is something villains use against Superman, but here his romantic partner feels guilty about using it because she knows it harms him, even though he's actively requesting it.
The "working through my childhood" line adds psychological depth to the joke -- Superman's home planet Krypton was destroyed, and kryptonite is literally a remnant of that trauma. The idea that he would fetishize the substance associated with his planet's destruction is a darkly comic take on trauma responses. The safe word being "Metropolis" (his adopted city) is a fitting detail that ties the joke together.