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

So there is this guy at her work that she spends a lot of time chatting with. She tells me "You might hear rumors about me having an affair with ....". 

Now I have always trusted my gf to be faithful and have not heard any rumors personally but she is being weird with her phone lately. She never lets it leave her sight. She almost panics when I go near it. She left her Facebook open and all of her conversations with this friend of hers have been deleted (possible that they only text on the phone, but he is at the top of her chat list).

 I know it's wrong for me to be checking this, but this is the only person on Facebook she (possibly) deletes her conversations with. When I asked to use her phone she took it from me and went to the dial selection ensuring that I did not veer from only making this phone call. She never used to be this way with her phone. Often when she returns from work, she says"So there's another rumour going around about me and ...." The other day she came home from work 2 hours late with the reason being "The delivery guy showed up late so I had to stick around".

Maybe its just me but it just seems like she is trying to hide something. How should I approach this situation?

I should also note The "friend" has similar issues as I do (PTSD). Perhaps she just vents and he offers her guidance on how to deal with it? Maybe she deletes the conversations because she thinks I might take it the wrong way. I feel like she truly loves and cares for me.

Yesterday she told me she had to work an event for 2-3 hours. I checked the place of business hours and it said they were not open until 4 (She had to work at 11am). I thought this was my chance to have some "for sure" evidence. Went to her place of employment (bartender) and sure enough, she was there..At work. 

Am I just being paranoid in trying to find something that is not there?
<bot>: Suspect something is up with my spouse considering how she won't let me go anywhere near her phone and shows up late after her workplace closes.