The duo snuck into Most Precious Blood at 32-23 36th St., near Broadway, about 1:45 p.m. and rummaged through the pockets of the 17-year-old boy's coat, police said.
The pair, a man and a woman, can be seen in surveillance footage released by police.
The man, who is in his 20s and about 5-feet-7-inches tall, wore a black jacket, dark jeans, black shoes, a red baseball cap with a black and red backpack, police said.
The woman, who is in her late teens and the same height, wore a bright blue jean jacket, blue jeans, a white shirt and black shoes, police said.
Anyone with information should contact Crime Stoppers at (800) 577-TIPS (8477).