So apparantly, the first volume of 3rei will be released in Japan next month. So this months chapter of 3rei was an extra chapter about Kuro and Illya learning about Mimi's being a yaoi fan and writer.
Spoiler for the chapter:
Mimi ships IsseixShirou, and Kuro wants to know who is the seme, Illya is horrified. And this appears.
Kotomine got an another cameo, at least.