This one's been around for awhile. As a fan of yuri, breast worship, lactation, and breast expansion, it bugs me how tantalizingly close this comes to fully incorporating all of my favorite things into one story. I always hoped there would be a sequel, but alas, nothing has ever appeared. Not only that, but RaTe almost never does yuri - everything else he draws is futa, I think there might be one or two panels in all of his other work that are strictly girl/girl. So I can't even enjoy his art in another context. :/
Oh well. Hope springs eternal, and maybe one day I will be able to just commission what I want. :D