The feeling that you get after a night of rough gay sex. It may also refer to how your ass feels after a hot curry. Sourbutts are usually extremely painful, annoying and irritating. They are like herpes. Sourbutts keep coming back.
1. I have such a Sourbutt after last nights hookup.
2. Dayum we all have Sourbutts after last nights curry.
3. My Sourbutt is fxcking painful.
refers to a situation during which as slug co-exists in a symbiotic relationship with slug-like host inhabits said host's butt in a mysterious circumstance