One of the many slang words for the arsehole, derived from the popular childrens' breakfast cereal of the same name (which happens to come in the form of chocolate cereal hoops). This noun can also form compounds and other expressions as follows:
Frosted Weeto (noun): when you end up with
cum around the arsehole after anal sex.
Bust a Weeto (verb): to have anal sex with someone for the first time (Note: implies
male rape rather than consensual sex).
Weeto Buster (noun):
anal rapist.
Crunch a Weeto (verb): to give a rimjob.