Booked award tickets-seperate cabin!
 

My fiance and I booked awards travel tickets with NWA for our honeymoon (from DTW to SFO) in August. We booked ours first, using my FF miles, and I was able to find a business seat on one leg (DTW-SFO). When FI booked his, he got a coach seat, and he's convinced now that he'd be more likely to get bumped up because of his Elite status. I would like to sit with him - what can we do at this point? Pay extra so he can sit in Business class with me? Thanks..

The first class cabin has been full for weeks on my flight. No guarentees. Arrive at the airport early, or upgrade now.

Provided there's award availability, he can change his ticket now for additional miles and possibly a fee.

I would do whatever it takes now to get the seat reserved. On our last several trips, none of our requested upgrades were available. Planes are full. It's your honeymoon, why risk the unfriendly skies?

How do we get this changed? Do we need to call the airlines and ask whether we can pay extra to upgrade?

You can't pay extra to upgrade award tickets. There must be award availability. You can check award availability at nwa.com but I'm not sure if you can change NW award tickets online or if you need to call.