I agree, female cats know when a male cat is unaltered, if you will. That is not to say that once you have Mooky neutered all will be heaven in the household.

I would turn up the TV, use a Walkman, drink wine and in general let them work it out. When there is a multiple pet household, usually there is a pecking order established and you cannot really control it. They have to work it out. If you are really lucky, it will run smoothly, if not, well, have a glass of wine, sit back and let them do their thing!

By the way, not everyone will agree with me about this, so I am mentioning this as my advice based on my experience and I am no way an authority on this.

I have tried many different ways of introducing cats to each other, and they have all backfired except to introduce them straight away (after the usual quaratine period if they are strays or shelter kitties...since you don't want to spread diseases....)...

Since you know the source of your cats then isolation for health reasons isn't such an issue.

Good luck. Keep a good sense of humor with the introductions and by all means, let us know what happened!

Cats will be cats.