The term “tubesteak sister full metal jacket” is a slang phrase that originated from the 1987 film “Full Metal Jacket”. It combines the slang term for a penis (“tubesteak”) with the term “sister” and the name of a type of bullet (“full metal jacket”).
The phrase is often used in a derogatory way to refer to women who are perceived to be promiscuous or sexually aggressive. However, it can also be used in a more playful or affectionate way, similar to the term “ballbuster”.