For guys: if you have a gf, for what reason would you screenshot other girls pics and keep it on your phone?

Anonymous
I'm curious if all guys do this? And if so, what is the purpose? I'm talking about regular girls or acquaintances not famous celebrities or anything. Just some random girls you see on Facebook or Instagram! Of course I'm a girl, I have insecurities and I would think that as my bf, he would have respect to not save the pics! The only thing that pops into my mind is that he jerks off to it when I'm not around. Like if it was some famous chick I would be more understanding but this is just heart breaking.
Updates
+1 y
I'm not psycho, I'm not going crazy over him having pics of his friends. It's of girls in bikinis or half naked. One of which we both know from work, and the others are just young pretty girls which he is more than 10 years older than so I know for a fact they aren't his friends or classmates.
For guys: if you have a gf, for what reason would you screenshot other girls pics and keep it on your phone?
12 Opinion