A walkthrough video is a recorded explanation of how to accomplish a certain task, usually beating a video game (or a particular level of one). A speed run is a walkthrough showing a particularly fast way to finish a game (or level). The man is implying that because he followed the speed-run video, intercourse didn't last long enough to satisfy his partner — who now probably doesn't want to date him again as a result.
The title text (humorously) shows what the narration on such a video might be like, based on typical video game walkthroughs. In a video game, a spawn point is a place where enemies, items, or players will appear; here, spawn is also being used in the biological sense of mating and reproduction. The "separate [...] more inside" part is similar to typical instructions about how to get past certain enemies or traps, while it could also refer to the labia majora and minora. Separating the labia majora would reveal the labia minora.
- [Cueball sits at a computer. His friend enters the room.]
- Cueball: How did the date go?
- Friend: I wanted to be prepared, so I looked up a sex walkthrough video.
- [The two men sit silently contemplating the words of the previous moment.]
- Cueball: ...and?
- Friend: It turns out it was a speed run.
- Cueball: Ouch.