The combination of the words "little" and "asshole." Adjective that is often used for careless rude people. Can also be used when referring to douchebags you previously dated.
A: "Are you still dating that guy?"
B: "Nah, he got belligerently drunk at my sisters wedding and started a cake-fight."
A: "What a lasso."
Lasso is a product by OmniPilot. Currently its at version 8. It is a language, an application server, a dessert topping, AND a floor wax! It allows for a webserver to poll a database and then to return the results of that poll to a webpage. And that's just the tip of the iceberg as far as Lasso is concerned.
Da "lariat" dat Harriet is "handy wif" due to her being such a pretty and charming-natured young lady.
Harriet may indeed be very expert at "roping" all of da misty-eyed dudes on da ranch, but it sounds like she practices "catch and release", since she keeps having to free up her "LASSo" in order to "snag" each of da different mushy-hearted guys in succession.