<human>: So we have been going out for 8 months and he's graduating while I still have 2 more years in college (He's 23 and I'm 21).
The story here is that I was using his phone the other day and it was open to a text with a girl I don't know asking her if she had thought about the past summer at all (before we were dating) she responded that she did once or twice and he responded "likewise". I closed the phone and I tried my hardest to put it aside. A couple hours later I thought to look at it again because I might have overreacted or read it wrong and I found that those specific texts with her were deleted but the rest of their conversation was still there. 
I don't know really how I feel about it or how to approach this. I want to let it go but I feel like I can't and I'm a little hurt. Should I trust him and just pretend that I never saw the text or if I should bring it up to him and ask why it is that he's deleting things and trying to keep things from me. Oh you should know that him and I use each other's phones and don't mind each other seeing texts normally.

Can you give me a shortened version of the text?
<bot>: I saw a text from another girl that was deleted later, should I let it go or should I bring it up to him?