I had two semi feral cats hanging around outside my house - a boy and girl - that I was feeding. A strange cat showed up and started fighting with my two around May but then it disappeared. I brought the girl inside and she was spayed 5 weeks ago. I'm saving up $$ to take the boy down to be vaccinated and neutered. For the past week or so the "stranger" cat has been showing up again and spraying my front door and around my screened-in back porch. Anybody know why? I keep cleaning areas that he sprays with vinegar but he comes back and marks it again. He never actually sprayed my door before I brought the girl cat in. Is there a connection?