Everytime go in also never ask me to show air ticket. Suppose need to show, but the staff never ask, so I didn't show.

If KLIA, they seldom ask for boarding pass.

However, my experience with previous LCCT and now KLI2, they do ask to see boarding pass. However, for lounge outside departure hall, when I sent my family overseas and I am not flying, I will just ask my wife to show them the boarding pass. And if you read previous posts, b00n just show them his NRIC. I guess they just want to verify it's our Priority Pass Membership Card or Credit Card we using to enter as we need to sign on the printed copy/slip before entering.