Cheating husband

I constantly read stories on here about relationships and cheating, and now what I thought was the perfect marriage is all a lie. We just had our 4th child 19 months ago....a little girl (our only girl) and as I was cleaning my room my daughter brings me my husbands iPad. As I grab it, it goes off so I look at the lock screen and see what I think is a pic but I’m not sure l. I can’t open it bc I don’t have the passcode so I can only see a small square picture, as I look more closely I notice it’s a picture of a girls vagina but it’s saved under a guys contact name, then a second one comes in saying “hey babe how’s work, we need to meet sun bc I’ll be busy sat” I immediately take a picture to show proof, as soon as i did that he opens it so it clears off the screen but thank god my camera snapped it before it went away. So I call him calmly and say hey what in the world was that......he proceeds to LIE to me and say that’s his homeboy from work 🙄😒😒😒😒😒😒😒 so a guy friend of yours is sending you pics like that......ok I give him the benefit of doubt and say maybe it’s a guy thing BUT..........WHAT I DONT SEE IS ANOTHER MAN CALLING YOU BABE ABD ASKING WHEN CAN YALL MEET?!!!! He hung up on me, is laughing saying I’m crazy but he doesn’t know I snapped a picture, I don’t know what to say or do bc we’ve been together 12 years and I’m just sooooooo fucking mad.

UPDATE***** so he’s now yelling at me saying that I’m crazy and it was a picture a girl sent his friend and his friend was showing him. Now I know this friend and I also know that his name is NOT the name of his “homeboy” and when I first asked him he said it was someone at his job now it’s his homeboy who doesn’t even work with him. But I’m wrong, I was snooping, I didn’t flip out and call him names, hell it didn’t even seem like I was mad. He won’t answer my calls and at this point I’m over it, it is what it is and I WILL NOT fight over a man EVER!!!!!