Sorry I'm not that offay with Android. I think it was a system notification, a 'Google' one. I doubt it was a Facebook one. And my partner doesn't use Google+ actively as far as I know. They may have stalked me, I'm not privy to their surfing habits.

They don't really use their Google account for anything but Google play, but it could be tied into their Chrome browser/profile somehow.

A long shot could be that we both visited the same *.wordpress.com site today.