Most Helpful Guy
cause he is over whatever it is that divided you two in the past and possibly wants to get back with you or at least be friends again
Most Helpful Girl
I've remained friends with most of my exes, but I have unfollowed them on facebook so I don't have to see their updates, especially because most of them are married/have kids.
Sometimes it is just a way to keep "tabs" on someone that you used to care about. Sometimes its just to see who is winning the break up.