And this is what happens when you try to mate with a koyukkuri. Still, not being able to get it in at all is one extreme end of the spectrum as to how viable it is. On the other, I saw one comic (which was a bit confused in its own right, as it had a stalk inside a Mamu Mamu) where an Alice rapes a Marisa and one of the Alices resulting from the rape then rapes a Marisa sister BEFORE THEY'RE EVEN BORN, resulting in the baby "giving birth" almost as soon as it's born, instantly killing said koyukkuri. I usually prefer an intermediate stance--before a certain age, any attempts at refreshing will produce a stalk that does not bear koyukkuris. (This goes both ways--a fully grown yukkuri raped by a ko-Alice would also have one of these babyless stalks). But, of course, every author/artist does things differently.