Regarding a host domain of host.com and a parked domain of park.com :

If a browser were to type www.park.com, would the browser's location bar show www.park.com, or would it be changed to www.host.com?

I know a variation of this question was asked for multiple domains. I'm hoping the same answer applies here.

It would show park.com
But it will show the same content as for host.com
If you need a different site you need an addon domain than.