Wtf Is Up With My Dad What Is He Doing?

Im 13 years old, a daddy’s girl, and recently I’ve noticed some suspicious stuff about my dad. He has a picture of a woman on his iphone whom I dont know. I thought it was one of my mom’s friend so I asked who she was. She was pretty I guess. My mom said she didnt know who she was. And like i asked my dad. He said he didnt know. Hes obviously lying. Maybe it was some1 from work. My dad isnt all that handsome either. Hes old and stuff. So I doubt he’d be dating whoever that lady was cause she seemed young and pretty for him. Do you think shes a prostitute?
Anyway, He always deletes his history on youtube on the iphone which makes me mad because I save all my fave songs there. And I asked him why? And said it was because of a virus and some other bull$hit. I didnt believe him and he got all mad at me and started yelling at me and started giving me the silent treatment like wtf? I just asked a simple question without any attitude or anything!!!
So today, my dad forgot to sign out of his youtube account and I saw the “recommended for you” thing and there was a bunch of weird videos of women and I scrolled my mouse to the “because you watched…”" thing. And he watched some weird videos. This scares me. I didnt tell my mom I dont want her to get hurt. And I didnt tell my dad because I know he’s gonna say its spam or virus or some1 hacked into his account. This makes me laugh a little who knew the man who is my dad would be such a f__king creeper?? I still love my dad but seriously wtf??
I lost a little respect for my dad. But atleast I dont have to feel guilty for asking him to buy me things.