You know cats will do what they want. We had a tom who decided he didn't want to live with girls so he moved out and lived feral. He was quite happy, I'm sure but we weren't. He took a fancy to a neighbour and started going to his house. On day, he was shut in, taken to the vets, given the snip and now lives happily ever after with Tim and his cats. We didn't like the idea of him fathering lots of litters when there are so many stray cats already. Male cats roam when they are unneutered. So, either do the same, or leave him to do his thing....