Several months back, I was at the B/E lounge at ATL on my way to Europe. At the counter was an AF Frequence Plus Rouge member (AF top tier) who was visibly upset at being denied access to the B/E lounge.

The agent informed him that a B/E boarding pass, not status, was necessary for entry into the lounge and directed him to the adjacent CRC.

He told her that since AF allows DL's top elites to access the AF business lounge at CDG with a Y ticket, why doesn't DL allow AF top elites with Y tickets access to DL's business lounge. I can understand his logic somewhat.

Perhaps AF top tier elites are grumbling to AF staff who in turn are purposely giving DL elites a hard time in a tit-for-tat.