Originally Posted by
Mark_T
Exactly.
The closest I could get to any impropriety in giving away your upgraded seat would be if you then claimed EXP benefits in the back having 'upgraded' a non-elite person into your seat.
Not of course an issue if you are both EXP as would be the case for you brp

I switched with my significant other before and still got EXP benefits in the back. FA somehow knew I was EXP and gave me the drink + food (plus more drinks and food). Maybe I got very lucky...