The fic I'm looking for is a SHINee/Jongkey AU wherein Key is deaf and goes to a school for those with disabilities. He befriended Jonghyun when Key decided to go on a bus without assistance (like Jonghyun paid for him). That's where he met Taemin who's also deaf but healed due to surgery. At first it was only Jongkey, but Key introduced Taemin and he felt being the third will because Taemin and Jonghyun could properly communicate...