CREATE TABLE table_name_10 (chosen_by VARCHAR(255), couple VARCHAR(255), choreographer_s_ VARCHAR(255))
What is Chosen By, when Couple is Katee Shean Joshua Allen, and when Choreographer(s) is Nakul Dev Mahajan?
    
SQL: SELECT chosen_by FROM table_name_10 WHERE couple = "katee shean joshua allen" AND choreographer_s_ = "nakul dev mahajan"