"Ou3a Yef'a3": Lebanese Slang, literally means "watch out it is going to blow up", metaphorically used by men when a snobbish hot chick passes them and does not pay them any attention.
Khosh Bosh - خوش بوش: Lebanese Slang, of unknown origin. The word "Khosh/خوش" in Farsi means "Good", and is used in some of the Gulf countries such as Kuwait in the local dialect. The expression as a whole describes a relationship between two people, which in principle is not expected to be close but somehow is, i.e. a vendor and his new business client, a person with another of much higher social rank:
Person 1: "I met the CEO of Nissan at an event a month ago"
Person 2: "wow, did you get to speak to him"
Person 1: "Man we became friends already, ana wiyyeh sorna Khosh Bosh [we became Khosh Bosh]"