I don't see any reason to feel guilty about a packet of crisps or two and a drink. There's really nothing of value that can be lifted from the Galleries lounges anyway. I have to admit I've done that a few times and might be more likely to now that the C-Gates Starbucks freebie is gone.

I have seen a lady totally shame-free emptying the biscuit jar (next to the coffee machines in GC) and putting them on a plate. Now that was impressive.