Welcome to our forum.
"I was wondering if my soon-to-be hubby, can have a girlfriend and I can have a boyfriend if we both agree to it?"
I don't see why not. Of course, make sure the said girlfriend and boyfriend both know what all's going on and are okay with it.
What other helps can we give? Do you have any questions or concerns? How about thoughts you want to share?
I hope Polyamory.com will be a beneficial place for you.