You can actually view it online
real people real animals
And you'll probably end up watching a snuff film since people have died attempting that.
If you're concerned about "real world logic" and if "a vagina can take a horse penis" have a look at some1 like "lilijunexx".
She's able to take 14+ inches of horse-d in her vagina (bad-dragon-dildo ofc), so it's most definitely possible especially because Marvin isn't that ridiculously sized compared to the average HC in 3dx porn.
I mean look at Animos "Brutus" from BTQ, that thing is INSANE! XD
All those toys that Lilijunexx and other people use are no where near as rigid and hard as an actual erection. They compresses inwards and downwards on themselves. You can even see this happening in a lot of the videos because the tube inside the dildo that shoots out the fake cum will be more visible and sticking out compared to the start of the video.
And even doing what she is doing takes practice. But still not comparable to a real horse.
I mean I knew it could be achieved but generally speaking most women would hurt themselves going for something so big. Now you can definitely stretch it over time, which seems to be the route the creator is going for.
Many women and men too have injured themselves or worse trying to have sex with an animal the size of a horse. Its not realistic in any way.
Since Pleasure3DX clearly intends to milk this series for as long as possible we'll see penetration following the same route the blow job episodes went. Next episode will be mostly hand stuff and then Marvin's tip goes in a few times as we get all the silly ecstasy/jealousy reaction shots from Emily and Amy before ending the episode with the girls talking about how good it felt but enough for now.
I am shocked someone hasn't starting doing what Pleasure3DX does but better quality, more than once a month, and with animations. Plus with AI assist tools these days.