Da famous lawman who belched a lot.
As heavily as Wyatt Urp drank, it's no wonder he was always burping and hiccuping.
(Actually, da real Mr. Earp was famously known to be an almost-teetotaler; his real weakness was ice cream, which I suppose could have made him intone an occasional "urp", also.
men will say urp when in an awkward situation. you signal you're uncomfortable and try to flee the event. you can also use urp when something is really funny or as an ice breaker in your marriage.
girlfriend: ok it's not my fault your grandma died.
boyfriend: urp, let's forget about it