I have a downstairs flat.
The tenant upstairs (in the only other flat in the building) thinks its funny to climb up onto my back garden 6ft gate, onto my porch roof, and up into to his bedroom window (usually when he's drunk or stoned and thinks its funny).
I have had to repair damage to the gate/fence post twice and now it's happened a third time. The gate won't close and is leaning down into my back garden, which is a problem with access to bins and compromises security at the back of the property.
I knocked on the door to ask (again) that the boy's Mum that she ensures he stops, and I asked them to pay for the damage, or at least half of it. She implied she had no knowledge and that her dear son wouldn't do such a thing, despite two separate witnesses seeing him in the act. Unfortunately one of those witnesses is the person living in my flat and he doesn't want to cause a disturbance so I doubt he would be happy for me to quote him.
I can't afford CCTV so thought I would file a police report for damages to my property and write to his landlord requesting he makes him stop. I also will try to buy intruder paint for the gate and my roof.
However, they own cats and leave the upstairs windows open so the cats can climb up onto the same fence and roof that the teenage son does. If I use intruder paint it will create havoc in their rented property and I don't know if it would cause the cat health problems. I'm sure it wouldn't taste/feel very nice to have paint on its fur that can't be easily washed off!
So ...am I being unreasonable to apply this stuff if I warn them that I am going to do it?