I read from cousin-german to covellite.

It looks like the use of the word "german" is using the old definition of "born of the same mother and father or grandparents".  

https://www.etymonline.com/word/german?ref=etymonline_crossreference#etymonline_v_6036

"cove" is not a combination of "convex" and "cave". https://www.etymonline.com/search?q=cove

The word of the episode is "couvade".

There's a bit more info here, although I'm sure you can find more somewhere else:

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