Neutered male cat keeps jumping on spayed female?

they've never been best of friends but they tolerate each other and sometimes even sleep next to each other, but every once in a while he will start staring at her with his tail swishing really fast and pounce on her and she will scream and run away or claw him. He sometimes does it with other cats male or female who live around us. One minute he's happily getting along with them and the next he locks in a stare, slowly creeps up and then jumps on them. He was neutered in the right time so i don't know if hes trying to mate or not and the other cats always run away before he can get into a mating positon if he is. Is it just a game he has or does he just want to mate even though his equipment is gone?