cat peeing on mattress

Hi Everyone,

I was having a problem with my cat peeing on my bed. It seemed as if I had stopped this problem a couple of months ago when I put an extra cat litter box in another area of the house (since I have two cats). I bought a brand new mattress and a waterproof mattress pad about two months ago and had had no problems. However, this weekend my cat started peeing on my bed again, and she also managed to puncture a hole in the mattress pad so that my new mattress got soiled.

Any ideas on how to address the behavior and/or ideas for a stronger mattress cover/pad that is scratch resistant??

Thanks!