<human>: Can you provide a brief rundown of the text in within 3 sentences?

I just get this feeling that my girlfriend keeps hiding things from me. She wants her own privacy and her space, and I respect that, but I can't help but feel she is either instigating or not terminating questionable conversations with "friends."

I know for a fact she doesn't clear her text history on her phone, or her chat history on facebook, but I really don't want to be the boyfriend that snoops. I've considered just asking her if she'd be willing to show me her conversations with these friends but I know she'll say no and that I'm either trying to invade her privacy or be controlling. I also know she has had a history of significant others blatantly snooping and invading her privacy so I understand why she may feel attacked by this.

Some reasons why this is my way of thinking:
She has a lot of friends, I know this, so she talks to a lot of people. Most times, when she's texting or messaging someone I may ask who she's talking to, and she tells me. Most of the time. Occasionally she just kind of mutters, oh somebody from work. If I continue to ask who, she gets defensive and accuses me of being controlling.
She also works at a fast food restaurant and closes most nights. I know sometimes she hangs out with friends when they close at 1-2 a.m. This doesn't bother me but if I ask what she did with her friends or what time she got home, she is vague and will say something to the effect of "stuff" and "late." This doesn't bother me as much as the messaging, but it does just kind of irk me and compiles on top.

I just need to know definitively what kind of conversations she is having with her friends. I know in an ideally healthy relationship, I should just be able to ask, and maybe this relationship isn't deemed to last, but we are both very outspoken about how we want it too last. I just want to respect her privacy but I also want to know what is happening. How should I go about handling this situation?
<bot>: I want to know if she is having potentially sexual conversations with friends without snooping through her texts, but I know she wouldn't tell me if I asked and she was in fact hiding something. Help please?