Greentext

This is like interpreting Dickens, let's see if I'm smarter than an English major

Isn't the world average supposed to be like 4 or slightly under at ~100 mm. Donkey Kong's are like wildly mutated freaks. Porn just needs them because a camera is in the way so diagonosexnastics is required.

They posit that the average penis is around 4 inches long, and that porn tends to employ people with abnormally large penises so they look better on camera.

It's a rather dumb plot hole IMO. I never met a drummer rocket scientist type. I'm sure they are out there somewhere, but pounding the cervix like a drum is a boring tune fit for an absentee-alpha brain. If that is what a person is interested in – ehh just consider me tiny to maybe make you feel a little better.

Here it's getting more metaphorical. They poetically compare sex with someone with a large penis to "pounding the cervix like a drum," drawing a contrast against someone with a more standard penis who has to use it more intelligently (a "rocket scientist" in this analogy).

If you feel self conscious, become a roadie (bicycle). Everyone says I won't wear the clothes and we all learn the clothes have a solid purposeful reason to exist. A few years of solid riding and you will not give a fuck about how anyone thinks of your junk. If you want to look, go ahead you dirty slut. I don't care if you look or that you are a slut.

Here they're poetically describing someone who receives anal sex regularly as a "roadie" or a "bicycle," i.e. one who gets "ridden" regularly. They're suggesting that once you've had a variety of penises of varying size inside of you, you'll feel a lot less self conscious about whatever you're packing.