Table schema:
CREATE TABLE table_name_10 (chosen_by VARCHAR, couple VARCHAR, choreographer_s_ VARCHAR)

Question: 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"