Umm whats this suppose to mean ADVICE???

i took my nephew for a walk to dunkin donuts (hes only one so he was in a carriage) i take him for a walk there everyday (cuz we like like down the street from it) and these random guys everyday always whistle at me and say " aye shorty whats up?" what should i say and what does aye shorty wats up suppose to mean (is it a pick up line) next time if anyone says that to me what should i say???