Yaoi where the uke grows up while seme is away??

I believe it's only a few chapters. And there's a couple where the uke is really short and cute (really into cosplaying too). But the seme leaves for a year or two on a business trip or something and when he gets back, the uke is grown up and looks nothing like himself. He convinces the seme that he's just the older brother but later admits to being the uke (while dressed up in cosplay). He was scared the seme wouldn't think he's cute anymore.

Anyway, hopefully that sounds familiar to someone. Does anyone know the name of the manga?