I have a pair that I really want to partner with other cats but they automatically re-partner. Is there a way to catch them right before it resets or anything? How do you make them not partner again once they have already been "repartnered"?
I'd first try the new 'KittyCatS! Break Free Bottle' which unpartners cats partenered less than 24 hours ago, for free. Charm never uses the auto feature, so I don't know for sure if it works and can't test it.
If they can't find each other (out of range, or one in-world and the other in the Cattery) when the partnership ends and a new one would begin, they should stay unpartnered. Note that if you wanted a box, this won't work for you.
And, of course, you can always run to the main store and purchase a break-up bottle.