Your cat is a bundle of joy. Right upto the point where you realize that she has relieved herself over your favourite duvet, the third time this week. It is near-impossible to rid the stench and stain associated with such deeds, and if this happens too frequently, it becomes a matter of bad hygiene for everyone in the household. I bet this becomes frustrating after the first few times, and you begin to wonder, why did my cat pee on my bed?
Instead of flying into a tirade against your pet, remember that it is against the nature of a cat to pee anywhere; peeing on your bed is a sign of deeper, solvable issues involved which need to be addressed immediately.