6-hours
Explanation
The Joke
The comic references the well-known medical warning found on erectile dysfunction medication: "If erection lasts more than 4 hours, call a doctor." In the first panel, we see a pill bottle with the warning (here saying more than 6 hours). The man calls the doctor, goes to the hospital — and in the final panel, the doctor and nurses greet him with a party and a banner reading "CONGRATULATIONS!"
The Humor
The standard medical warning about prolonged erections is meant to convey a serious health risk (priapism, which can cause permanent damage). But the comic subverts the expectation that the doctor visit will involve urgent, embarrassing medical treatment. Instead, the medical staff treat it as an achievement to be celebrated — as if having an erection lasting more than 6 hours is an impressive feat of virility rather than a dangerous medical condition. The humor derives from the contrast between the clinical seriousness of the actual warning and the absurd idea that doctors would react with admiration rather than concern. It also plays on the cultural association between sexual performance and masculine pride, taken to a ridiculous extreme where even medical professionals abandon their professional duties to throw a party.