The first time you speak to Kurtis Swindell at the entrance to the boardwalk, he'll refuse to let you in until you show him your ticket - and no amount of arguing will make him budge.
You'll get a family ticket to the boardwalk from Dr. Ernald P. Whimple once you've gotten rid of all the hobos as part of The Nobel Pee Prize. Give it to Kurtis and he'll let you in, after you explain the nature of your "family".