Thanks everyone for their responses this was a very touchy thing that actually I'm glad happened (as weird as it is to say) as it came with growth.
I did bring up everything I said and the idea of restoring her texts did hurt her but she said if it's what I need fine. The "dick pic" in question was out of the blue, it literally was them talking about spirituality (something she has recently taken to) and she sent a picture of herself fully clothed, smiling with thumbs up, the same picture she posts on her social media. The next message was a dick pic to which she said what the fuck to which he said "sorry gave up masturbation for lent sorry" and then she went on like nothing happened.
What did come out of our talk is she does realize why I feel the way I feel (the secrecy) and as to the "why not tell me?" was cause she wanted to pretend it didn't happen. Which led to a real realization on her part that when something bad happens in her life she just likes to ignore it with the hopes everything will go back to normal. As before we met she was sexually assaulted by a coworker, kept it to herself and worked in the same building with him for years (something I already knew).
She apologized that she ever let it get this far, understands that secrecy CANNOT happen like this ever again, and most importantly (for her) she went in to talk to her boss about what happened and she is not comfortable working with him anymore and he is working on maybe getting rid of the guy completely but at least keeping them apart. In turn she has changed a very self-destructive habit she has, carrying creepy assholes baggage for them.
I learned a little bit about myself as well as another factor to this whole thing was during the months of their friendship I was in a funk, sitting around all day, not communicating, playing video games all day etc. Started working out HARDCORE (already lost 5lbs) and am working on myself more now.
In the end I do believe this has made us stronger and obviously if anything like this were to ever happen again that would make it a pattern, in which case I would be gone but I don't believe that is the case, she was so sad and so sorry that it got this far.