What reasons have you had for neither accepting nor declining a facebook friend request?

A few weeks ago, I friended a guy I’ve been seeing. He did not accept my request, but he did not decline it—it’s been pending for weeks. Tonight, my facebook feed told me he became friends with several other people.

Up until that, I figured he just hadn’t logged in lately or hadn’t paid attention to his friend requests. We spend time together regularly and don’t have any weirdness between us that I can think of.

Naturally I guess I will have to ask him about it at some point, but in the meantime, would anyone care to speculate or provide some perspective? What reasons have you had for keeping someone in this holding pattern?