Male cat problem?

First off, I'm not trying to be distasteful or anything so forgive me if this is offensive.
I adopted a male cat yesterday. I have several cats already and I have had male cats but I have never seen this happen.
I was petting him, in an appropriate way of course and not in any personal areas, and he appeared to have a male reaction. My concern is that perhaps he is not neutered as I was told he is?
I have never had any of my male cats "have their little friend come out of hiding" so that's why I ask.
The cats is about 5-6 months old and according to his papers was neutered earlier this month.
Thank you in advance for your help and I'm sorry if this is not an appropriate question.

Ishtaka

Just what denomination is your cat?

I'm sorry, I don't know what you mean.

It's not inappropriate, don't worry.

Neutered males are capable of an erection. Sometimes, you never see it. Sometimes you may only see it when they are cleaning/grooming it. Also, given the fact that he was just neutered, he does still have those male hormones. It takes around a month for the hormones to cool down. But his equipment will still work...but he'll be lacking the the hormones, urges, behaviors, and ability to imprengnate a female.

ETA: my cats are undecided on their "denomination" I don't understand that either.

All neutered cats 'show' occasionally - sometimes when grooming themselves, sometimes as part of dominance behaviour or just if they are having fun! Wellington, currently my only neutered male, has a reaction when he is kneading on me sometimes. He also actually tries to mate from time to time, but of course can't.

Originally Posted by ahem

Just what denomination is your cat?

Click to expand...

Sorry but that made my laugh

Radar was neutered months ago and still occasionally 'shows'

A couple of months ago I was petting Tomas and looked down to see him..... I looked up at his face and said "Well, it's certainly time to get you neutered" off to the vet he went a couple days later.