need advice

Okay when I break up with someone so does my family my cousin never met my ex has my ex on fb and likes all my ex post with the new girlfriend my sister has my ex as a friend on fb my sister don't like my ex because that person played the shit out of me now I go on fb and see a post my sister liked of my ex and the new girlfriend and along ass paragraph which is funny because when I post pictures of my gf etc my sister or cousin don't like it now I can care less about my ex I just think it's fucked up how my sister is moving