I was going to say "If you find the proposition interesting, you might be pleased to know this image is also the cover to a doujinshi by the same artist that focuses on these three" but then, it's not an adult doujinshi, so perhaps maybe you wouldn't?
Hahaha. Well, Either way, I might as well share the information here. The title is だから私はあなたたちの父親ではありません! (Which I believe translates to something like "Therefore, I am not your father!") by the circle 錆色 (Sabiiro) - it went on sale at last years Comiket. I checked around to see if maybe it had been uploaded anywhere, but didn't spot it. I've seen at least one copy of it turn up on ebay, though.
