There was a SciFi show Babylon 5 that had some invisible parasite on some character's shoulder that you got to find out about and see eventually.

Yeah, anal sex in general sounds quite disgusting, and there are even people putting their faces in that area. WTAF.

I worked at a hotel that had a straight-acting gay bartender and his "Girlfriend" ended up with a perforated colon or something and it was quite serious, maybe killed him.

Nothing can beat a vagina, its warm, has great natural lube, and little quirks that feel good... Wanting another man's butthole is a mental disorder and makes deworming your kids an important thing...