Scott Disick In The Arms Of Another Chick In Miami Just Few Days After He Was With Kourtney Kardashian And Her Family In Costa Rica (Photos)

Scott  Dickson popped up in Miami on Monday with a very young looking hot babe ... on the beach and in the pool at the Setai Hotel.

Just few days ago he was chilling in Costa Rica with Kourtney and their kids. He even proudly posted the picture below.

This Miami mystery girl is a hot model he casually met and "hung out" with for the day ... at least that's what she's telling friends.
The cheeky chick is Jessica Harris -- professionally known as J Lynne -- a Next model from Philly who recently moved to Florida.