What are the chances of getting a cold sore as an adult if you never get them?

Depends on exposure: If you are exposed to herpes you can catch it, at any age. Once you've had a cold sore (herpes outbreak), you can't say you never get cold sores any more.

Moderate: Cold sores are caused by a virus. If your spouse or partner gets cold sores then there is a good chance that you will be exposed to the virus. If you are exposed enough times you will likely contract the virus yourself. You can also get the virus by sharing drinks or cups. You can also get the virus from your child if he/she catches it at school/daycare.