Would it be OK if the OP made the switch after the meal service was completed and did not request any free alcohol?

How do you feel about a BF pax sharing their meal or sundae with their companion in coach? If I decided to walk my sundae back to my coach friend, would you object? I am just curious. I did this on some DL flights years ago (my friend and I didn't switch seats inflight, we just took turns riding the whole trip) - usually never had a problem, but one FA gave me a hard time so I retorted it was my darn sundae and I would do what I pleased with it. I honestly felt FAs had more important things to do than intercept inter-cabin food transfers.