Friend never talks about children

[Anonymous]

OP, I don't find your question odd, or your desire to know the reason behind it odd, either. But I suggest you ask some "real" people since everyone here is really bent on telling you to mind your own business instead.

I do agree with some PPs who have said he may really have nothing to add, and no interest in kids or connection to them in any way.

[Anonymous]

Do you not realize that kid-talk is boring, esp. for people w/o kids. He probably finds the subject boring and is hoping by not joining in the conversation, you will eventually change the subject.