After
Explanation
This comic is a post-apocalyptic joke about terrible pickup lines.
The single-panel scene shows two people -- a man and a woman -- sitting on a rock in what appears to be a hellish, post-nuclear wasteland with flames and destruction all around them. The man delivers the line: "Yeah, so how about we nuclear arma-GET-IT-ON." This is a pun on "Armageddon" (nuclear armageddon) mashed together with "get it on," turning a reference to the apocalypse into a sexual come-on.
The caption below reads: "This was not the only reason humanity died out, but it was the last reason."
The joke operates on multiple levels. On the surface, it's about a spectacularly bad pun being used as a pickup line in the worst possible circumstances. The caption adds a layer of dark absurdity by implying that humanity had already been doomed by nuclear war, but this awful pickup line was somehow the final nail in the coffin -- perhaps because it was so bad that the last two surviving humans refused to reproduce, or simply because it represents the quality of human decision-making that led to the apocalypse in the first place.