Slimy amalgam of bodily fluid (semen, sweat) emitted by an obese man during sexual activity. Originally used by sex-workers to describe the attentions of a particularly unattractive client.

well i'll be fucked in an irish accent if spoken quickly

If said really fast, sounds like a swearing irishman.

The written equivalent of many spoken terms, which expresses surprise which is somewhat more than mild, but which will also avoid potential removal for unsavory language.