Stay within the entrance area, until the next guests comes in and ask him nicely, if he might take your 2nd guest as his guest.
I have done it a couple of times on different airlines after witnessing lounge wardens turn away too many guests.
Thin line for the agents, but in that case, a young well dressed SEN was told that his parents, an elderly couple in their 70`s, cannot enter the lounge with him. Another case I remember was a NWA warden, still during the old DTW terminal days, turning away a KL Silver Wing with his 4-5 year old daugther right in front me. Despite getting the looks from the agent, I was more than happy to help out a fellow traveler spending some hours in the lounge instead of the crappy terminal building.
Normally I appreciate agents playing by the rules, but in some cases, like the two mentioned above, it was simply ridiculous...