When a Facebook post says a person is with another do they actually have to be together?

Simply put, tagging identifies someone else in a post, photo or status update that you share. A tag may also notify that person that you have mentioned them or referred to them in a post or a photo, and provide a link back to their profile. You can tag someone in a photo that you share to identify them in the photo. You can tag someone in a status update to make sure that they see that post.

If you want to get someone’s attention on Fb, you can tag them in a comment by entering their username preceded. So when a Fb post says a person is with another, they don't have to be together.