My ex hasn't added me to his Facebook but it's still open? It's been 3 weeks.?

[some guy]

I'm not sure about something - are you saying your ex boyfriend hasn't added you but you expect that he would or are you saying that you added him and you're not sure why he hasn't accepted your request you sent him?

The reason I ask is that, as far as I'm aware, facebook doesn't notify you when someone declines a friend request you send so, if you sent him one (I'm not sure who's doing/done the sending) then you'll never know why he may have turned it down.

You could always just message him and ask. I mean, if you're willing to be friends on facebook then there's no reason why he wouldn't respond. Plus, given that he's your ex boyfriend (I don't know what the circumstances surrounding the breakup were), if he received your friend request and said no to it, stands to reason he'd be annoyed and probably block you. In this case, just seeing if you can message him will tell you whether or not he's done this.

(I'm answering this neutrally based only on your question. It's not my rite to point out that adding exes isn't always a good idea. Hope it works out).