SO watching hardcore porn: do I bring it up?

My SO and I have the same phone. I picked his up this morning by mistake and went to safari to search for something. His browsers were filled with porn, some really hardcore stuff (abuse porn etc). We've never talked about this, and I've never talked about it with anyone. It made me feel horrible and worthless. 
Is this normal? Do your men watch porn? Do you talk about it? I don't know what to do.