I got away with a guest on the same flight LHR-DXB having dinner with me from WTP, i stated my guest had never been in First b4 and would they be allowed to have my meal instead of me and the crew member said of course not you may both have a meal and really spoilt her ^ Hopefully you will be lucky try and corner them b4 your mums in the cabin .
Buts its all uncouth/disruptive/taking the piss at once