Odd question, but bare with me.

We're flying LHR to Dubai for the holidays, but I've managed to get myself a business class fare as there is work involved for me whilst in Dubai. My spouse and little one are flying Economy (begrudgingly).

At some point during the flight, I'd like to give my wife a break and have my 4-year old sit with me quietly (watching a movie) or something of the sort.

Is it easier if I'm at the front of the upper deck or back for access between floors? It's unclear whether the rear stairs are in use as they lead into the aircraft bar, so I'm not sure there's a pass-through.

Thanks,
mflat