my ex added me back on fb, really short answer, plz help?

[XICarmenIX]

1. Accepting the friend request
- He might think that you're okay with him
- You want him back
2. Ignore his friend request
-You can't be bothered with him
- also means you still hold a grudge
3. Let it be
-you still care about him cuz you're keeping the request and thinking of whether to accept it

If I were you. I'd confirm the request. But I wouldn't chat/MSG/comment on any of his stuff on fb cuz if I were to do it. I'd seem desperate.
Only if he talks to you. You reply. But with short statements and not so personal stuff.
Just treat him as a friend that ain't close to you but you know him.