Why make a will?
Most people never get a round to making a valid will. This isn't ideal in any situation, but if you live with your partner and aren't married/civil partnered it can be a disaster. Your partner could find themselves out on their ear, homeless, with no money or savings, no right to organise your funeral or sort out your affairs, no keepsakes to remember you by even.Their only hope would be that, under certain circumstances, they might be able to take the matter to court - this would be expensive, stressful, drawn-out, damaging to family relationships, and there's no guarantee of success. If you think you don't need a will, you are almost certainly wrong.
At the very least making a will protects your partner, family and friends from a lot of stress and confusion over what you intended them to have, or to take care of, and who you wanted to be involved in your funeral, as well as protecting those you care for from financial or other hardship.