enhancement
Explanation
The Joke
A man tells a woman he is thinking of going in for a penile enhancement surgery. She responds with typical body-positivity advice: "You'''re a perfectly fine body! Why not just accept yourself? Love your body. Nobody is perfect, but are we so vain that we would undergo dangerous surgery just for a bigger organ?"
The man then reveals: "Actually, I was going to get it lengthened, sharpened, and made to vibrate." The woman immediately reverses course: "Get your clothes on, let'''s go! I'''m calling an ambulance" -- meaning she wants to rush to the hospital right away to get this done.
The Humor
The comedy hinges on a bait-and-switch. The woman initially takes the moral high ground with a body-positivity speech about self-acceptance. But when the man reveals that the "enhancement" is not merely cosmetic but involves features that would directly benefit HER (vibration, etc.), she instantly abandons her principled stance and becomes the most enthusiastic advocate for the procedure. The joke satirizes how easily high-minded principles can collapse when personal self-interest enters the picture.
The absurd specifics of the enhancement ("lengthened, sharpened, and made to vibrate") push the joke further into comedy by being simultaneously ridiculous and, from the woman'''s perspective, irresistibly appealing.