Am I freaking out?

Yesterday I found 2 pics of a girl on my husbands phone. These where not sexual pics or anything like that but they were pics of her with her finger stuck in a wipe container. One where she was laughing at my husband. He said he took them to "black mail" or "embarrass" her and he meant to transfer them to his iPad at work. I flipped why does he have the pics? What's the point in all that crap? And why go through the trouble to embarrass her? I don't get it. And how do I know he doesn't have other pics of females on his iPad at work? If he would have transferred those before I seen them I would have never known about them. Did I over react?

UPDATE

so he apologized and said it was careless but I've already caught him in a lie. Last night he said he sent them to his boss and today he said he meant to transfer them to his iPad. He swears nothing's going on I wanna believe him but who knows what else is on the iPad. He also texted me and said he should have just deleted them so I wouldn't have seen them and then apologized that he took them on his phone. And the way he said it makes me think he regrets using his phone and not his iPad bc I seen them.