Searching for a transformation story.

Story by Blurpee

I'm struggling to remember a story I read about a year ago, though that very likely was not when it was posted, about a girl being transformed into a futanari.  I thought it might have been on The Changing Mirror, but I've been unable to rediscover it there.

Anyways, from what I remember, a girl either moves into a new apartment or she gets new neighbors in her apartment. The neighbors keep her up all night with their sexing, and I'm pretty sure she meets them as she's getting off the elevator at some point and thinks they're dressed like whores which plays into the sexual escapades.  After several nights and / or weeks of this, she eventually goes over to confront them.  One of the futas answers the door and that's when the cat gets out of the bag.  From there its pretty standard sex stuff for awhile, but then the girl starts to grow a dick of her own.  She's all for it and eventually moves in with the two original futas.  I'm pretty sure one of the futas was black and the protagonists was asian.  I want to say that eventually they rope a fourth person into it all, but I could just be making that part up, I don't remember the ending as well as the set up.

Thanks for any help.