I think the breeder section might help you out. I don't breed, so I really don't check in there very much.
I know there's a few (at least) people here who have Yorkie-poos (isn't that what the mix is called?), so maybe one of them might be able to help you too.
I personally would just never have an unneutered male and female together b/c I don't want to breed or deal with any of the issues of breeding (adopting out, etc), but I thought it was funny when you said "they must have thought they were on a romantic holiday"; that tickled me for some reason
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Good luck with all of it!