This sort of thread is exactly the reason I wish BA would issue all Silver/Gold card members with 2-3 lounge passes per annum to permit them to exceed the "1 guest" rule on a small number of occasions.

It would take the heat out of the process at all levels - the lounge angels would have a means of controlling the situation without resorting to a flat no ("Of course you're welcome to bring in extra guests, can I have the lounge passes? Oh gosh, you've used them all - I'm afraid that we can only let you bring more than one person if you have passes for the additional guests today"), and from the travellers perspective, it would balance all those miserable day trips to the continent where you were on your own in the lounge.

It would also address the perennial questions of babies, children, nannies, people you've met off the street - no pass, no guest, but a bit more flexibility towards loyal passengers.