So when she goes out and partys she get her self into trouble and then calls my bf to come save her just a few examples.

Why does your bf feel it's appropriate to go rescuing this girl? Seriously, she's old enough to take care of herself.

She also seems to msg him and me different things. example of what i mean is she will tell me shes coming over and taking the bus and then msg him for a ride and ill find out when hes leaving.

Does your bf know that? Why does he cater to all her needs? Why doens't he put his foot down? Why does he need to get rude when you want to see their messages?

Im pissed and think hes hiding somthing my phone is not password protected he wants to see somthing ill show him i have nothing to hide he could go through everything on my phone i would not care. makes me feel like he is hiding somthing

Your bf should behave completely different. He's cheated on you in the past and he should do everything to regain your trust and make your relationship stronger. He's not doing that, so you're not wrong here. I couldn't put up with this bs and would break up with him. But maybe that's just me. Don't you want to be with someone who respects you?