Well, there are many different types of rhythm. One of the most common is observed in haiku, the 5-7-5 rule.
Here's how it works:
See, the Japanese censor their genitalia in their adult movies and hentai, but not sperm. Thus, they have moved on to making movies from what is called Bukkake (heavy waters). Which consists of beauty secrets like facials and full body hydration.
How this ties in with Haiku? I'm getting to that. They measure the load of each male and make a cross-analysis with their size, then they divide the men into "Haiku Groups".
Starting off, they get the men who only need to fap 5 times to release, once they go through the first string, you get the halftime show of bigger loads with bigger sizes, these need 7 faps to release. Then, when the second half comes around until the end, they get the 5 fappers again for a speedy finish.
Nature's rhythm at its finest.