Thanks nux; During a domestic later this month I'm hoping to arrange a lounge meet-up and have my first look at the Flounges in T5 so presumably once I'm in they won't be aware that my host will leave without me..
Genuis1, are you saying the opposite: that the boarding card is put on to the system as valid, allowing re-entry for the guest, as if eligible? I enjoy the lounges but I like to get out and shop/spot on occasion (particularly if I'm there for a few hours), before refreshing myself again with a glass of something fizzy..