nerdy-kids
Explanation
The Joke
In the top panel, two nerdy-looking parents are telling their child a sweet origin story: they explain that they were two nerdy parents who wanted to create a little nerdy kid, and that is where the child came from. The kid responds with an endearing "Aww..."
The bottom panel, labeled "Five years earlier," reveals the actual truth. The two parents are in bed, and one says "The condom broke." The other, applying a very literal, nerdy problem-solving approach, responds: "Try taking it off and putting it back on." This is, of course, the classic IT troubleshooting advice ("have you tried turning it off and on again?") applied absurdly to a condom malfunction.
The Humor
The comic works on two levels. First, there is the classic gap between the sanitized story parents tell their children about how they were conceived versus the awkward reality. Second, the punchline is a perfect nerd joke: when faced with any malfunction, these nerdy parents instinctively default to the universal tech support fix of restarting/resetting the malfunctioning item. Applying "turn it off and on again" to a broken condom is both absurd and perfectly in character for the type of parents described in the first panel.
References
The "turn it off and on again" troubleshooting advice is a ubiquitous trope in IT support culture, famously popularized by the British TV show "The IT Crowd" (2006-2013).