Logical operators - Multiple pages

I'm using this:

{{ if page_url != "/portfolio" }}
  <footer>
      ...
  </footer>
{{ /if }}

to exclude my footer from the portfolio page and is working the way it should, the footer doesn't show up in the portfolio page. How do I exclude it from another page in addition to the portfolio page?

I've tried:

{{ if page_url != "/portfolio" || "/contact" }}

and

{{ if page_url != "/portfolio" || page_url != "/contact" }}

and other combos, but it didn't work.