I'm one of those lowly non-elite members.

If it was a short flight, I might stay back in coach, just to be able to sit together. On a long flight, the upgrade would be very hard to pass up. Depending on the relationship between all of the group, the answer could change.

If you are all close buddies, then I am sure your friend and father would ont begrudge you the upgrade. They'd probably joke about it, and that would be that. Of course, you and your dad had to fly a fair amount in order to reach elite status.

I suppose if you wanted, you could let the fathers have the upgraded seats and you sit with your friend in coach.

Sorry I cannot give you a more concrete answer, but for me, a lot would depend on the specifics.