Every time I touch the bit on my cats tail, where its attached to the cat, the cat kind of bows like its preying to Macca?

That's a really sensitive area for cats. Its like scratching behind a dogs ears. It feels REALLY good, so no its not broken, just in bliss lol.

Cats enjoy being scratched at the base of the tail because there’s a lot of nerves there. But don’t do it for too long at one time because they can get overstimulated and it might start to become uncomfortable or painful for them.

The vet will tell you when you take it down to see them

It means he likes a butt scratch.

They call that area the root of the tail. When you skritch a cat at the root of the tail, there's a nerve that often causes the back legs to stretch. It is somehow a pleasant feeling for a cat.

We had one cat that had a strong reaction to being skritched there. His back legs would straighten out so tall he would sometimes fall over sideways. As kids we thought that was pretty funny, and would try to make that happen. The cat didn't mind. He got extra pets and skritches, so it was all good.

you need to have the vet check your cat

your probably turning it on .. go for it ..