Please help! Cat with inappropriate toilet habits.

[Unplastered]

I hope someone can give me some advice, I am just about at the end of my tether with my cats.

I have a 15 year old neutered tom and and a 7 year old neutered female. They have never been the best of friends but have always tolerated each other. We've had them both since kittens, microchipped, wormed and flea treated, both in good general health. We have a 4 yo who is very good with the cats, and they seemed to accept her arrival - no problems when I was pregnant with her or when she was a baby.

The tom has never ever used a litter tray and always gone outside through the cat flap. He still does - but not always, he has taken to occasional weeing (not spraying) in the house. It's in different places, not hidden behind furniture or anything and he doesn't seem to mind if we see him at it. I have seen him come in through the cat flap, walk into the living room, wee in the middle of the floor right in front of me, and walk straight back out into the garden again!

The female is a bit different in that sometimes she will spray (in a couple of different places, repeatedly) and sometimes it is wee, but her habits are odd. She used to use a litter tray, and we have tried different types of cat litter, covered and uncovered, different locations and always kept it very clean but she has just stopped using it. Sometimes she goes outside to wee, but I keep catching her at it in the house. Yesterday I caught her on the Worktop in the kitchen, balanced on the edge of the sink very carefully peeing into the kitchen (empty) sink!!! My husband says he has seen her doing the same thing on the toilet, balanced on the seat peeing into the bowl! Neither of them wee on the carpets, preferring the tiles and wood floors thankfully.

I don't know what to do. I obviously clean everything very thoroughly but seriously, the kitchen sink?!! I am 35 weeks pregnant with no. 2 and I am dreading the thought of having to bleach the kitchen every time I go in there, and frankly I am sick of finding puddles of cat wee all over the house. This can't go on! Has anyone got any ideas what might be causing the problem and what I might be able to do to help stop it?