"Mkhallfo w Nessee?" is an expression which literally means "Did I give birth to him and forget all about him?", metaphorically, it is a Lebanese slang expression, which metaphorically means "I do not have to do him any favors".

Sample conversation:

Person 1: "why did you not help him pass his exam"

Person 2: "i barely know the guy, shoo mkhallfo w nessee ana?"