Just to make things clear:
Upon entering to the lounge you will notice a stand with touch screen, barcode reader and card reader. You can use this station to gain entrance to the lounge;
You will have 3 options:
- LY business class.
- Gold (and above) or KD.
- Guest.
Press the second option, than let the computer read your card and boarding pass, and you will gain access. Than start the process again, but press guest this time. Your guest will gain access as well.
There is no human involved in this process (although you can ask the attendant at the desk to allow you entering the lounge as well). The computer knows the rules very well (better than everyone else) and will allow the two of you to access the lounge. Therefore, whoever told you this is absolutely wrong - even if it was an LY official.