I would just set up a tank while they were at work and let them find it. They would be super pissed and say no more. then they would love the tank. Wait a couple months and repeat.
ha i just moved out and now im gettin a 120
i was upstairs at my moms house so i could understand her concern
but we are both happy now
but when i lived with her a would set them up while she was gone and she wouldnt notice for weeks and when she did i would give her the ole you didnt even notice so how does it bother you routine works with snakes too