Is It Immature To Delete An Ex Off Facebook?

[Paris]

I had a very painful breakup recently..he broke up with me over a text, giving no reason just the " It's not you, It's me and i think it's for best" ....I don;t know what happened and what made him to act like this..I am devestated, tried to reach him and talk to him but he ignored me and my messages/calls comepeletly..... Im still hurting.. he is still on my FB.. acting like nothing has happened between us.. posting inks and sharing stuff ...should i just unfriend him? idk wut to do.. we have a lot of mutual friends too..what should i do? need your help...