I have a bit of similar question.
I am going with my mum in 3 weeks. I have a Dreampas, so 20% off in the shops.
Would they make a problem of it if we go pay together (so I am present, yet we just pay her and my stuff in one go in stead of paying separately) or if she pays for the whole amount (using my AP discount)? Or do I actually have to put her wallet in my purse so it looks as if I'm paying for everything?

I mean, for all they know she's keeping my wallet in her purse or something...
I know my mum and seeing as I payed for the trip she'll want to pay for all the food and souvenirs and stuff, yet I would feel really bad if she'd have to pay everything at full price, knowing that I get a discount with my AP.