Euphemism for horsefucker. A horserider is often a statistics or security studies student who goes around fucking horses and one day ends up in a wheelchair cos they get kicked by a horse.
Luke used to be a horserider, he tried to have sex with a horse, but it kicked him and now he's in a wheelchair and his dick doesn't work.
Breaking a bottle of chloroform to knock a horse unconscious, then proceeding to insert the horse's penis into your own ass or a partner's, only to have the horse awake mid-fuck and ram the individual's asshole so hard it ruptures his or her intestinal wall and they bleed out. Usually the death occurs in the field, the hospital bed or during the act itself.
Robert: What the hell happened to Todd, I heard he died?
Lee: He totally chloroformed that horse to try to have it fuck him, but it woke up and totally Polish Horse-Rider'd the shit out of him. Literally.
Robert: Shit, well what the fuck happened to the horse? I was going to fuck it.
When you are doing a girl doggy-style and she shits so your penis is all covered in shit, then you put her down on a table and put the shit and cum all together on her tits and smear it all around. Then you perform the Rainbow Kiss. Better effect without the woman's consent.
Chris: When i had sex with Hannah she shat all over my penis and then she was on her period so I did the Texas Horseride
Gaben: Damn bro you need to chill