A regular on a show playing someone else is always a risk. It either succeeds to a high degree or fails. This succeeds.
After Jesse spends the the week in Greece following his grandfather's funeral, he brings back his cousin, Stavros (also played by John Stamos) for a visit. Stavros and Jesse used to be like brothers. But things change. Now, he is a rude, shady, womanizer. Jesse doesn't believe the family because he thinks they don't understand how passionate Greeks are. They must catch him in the act before he pulls off a major stunt.
Stavros being a con artist is hilarious, but it is Stamos' talent that makes this an awesome episode.