The route is not within Europe. Connecting from non-Schengen at CDG in both directions to/from USA. All flights are marketed by AF, but the TATL sectors are DL.

Had no issue booking seats on DL, but AF is the issue. I have DL status but nothing with AF (and didn't think they'd care.)

Online, the seatmap is grayed out for the AF legs even though it shows my seats for the DL legs. Called and was told it's simply not possible until 30 hours before the flight at which point I can select seats. I asked, "what happens if there aren't seats near each other - I'm traveling with a baby," and he gave me the bad news that, "whatever happens, we board you first and make sure you sit with each other." If that's really the case, sounds like I could be screwing someone else out of their seats, and have them give me a death stare all flight because I didn't do in advance what I couldn't do!