<human>: Give me a shortened version of the text

I've been with my girl for just over three years. We've been living together and overall things have been decent. About the normal ups and downs of any relationship. Until lately.

I noticed about a week ago that she started acting very protective of her phone. Something she's never really done before. Like she's been putting it screen down all the time (something she's actually called me out for before), and taking it to the bathroom with her almost every time she goes (see previous parentheses).

It caught my attention, but I didn't think too much of it until we were driving at night and her phone lit up with a text from a guy saying something cute about a snapchat she sent. 

Adrenaline!

I didn't react to it, nor have I done anything yet to confront her. But unfortunately, and I'm sure I'll get shit for it, I ended up going through her phone last night. Here's what I've found:

--The only person she sends snapchats to is the aforementioned guy. 
--She also has been deleting their text conversations on what seems to be an hourly basis. However, she isn't deleting any other ones.
--She's also been deleting just her text logs exclusively. (No idea why that is necessary at all)

My alarms are going off. I don't know what to do about the situation. I'd love some advice or even a way to prove my gut feelings are correct.
<bot>: Girlfriend of 3+ years just started acting shady with her phone. Saw a cute text from a guy. Went through her phone (I know, I know) and found suspicious behaviors.