Facebook block problem

so this guy I am trying to be with has my Facebook information and he logs into my Facebook to check my stuff to make sure I'm not talking to other guys or lying he blocked an ex of mine on his phone but then when I logged into my phone, my ex wasn't blocked anymore. then the guy that I'm trying to be with logged in and saw that he wasn't blocked and thought that I unblocked him when I didn't. has this issue happen to anyone else it is causing a huge fight even though I did not unblock him I don't know what to do because I don't have an answer for why my ex got unblocked I don't even like my ex I don't want to talk to my ex so I have no reason to unblocked him why did he get unblocked when the transfer between two phones?