It's vagina and Penis in our house that way it should be, it was funny when Reny and Reth found out what was the difference between them and Rory.
We explained and then Reny said "Yeah but daddy's is bigger!" and Reth said "No daddy's not bigger it's hugiiiie!" (Nudity is not a problem in our house) But that was indeed funny, Memories!!!

And now Reth says "Daddy has a penis and mummy has a vagina"