Am I in the wrong?

Lily-Anne
Today I was on Facebook and saw pictures of my boyfriend and two girls who he goes to an education centre with, and he had quite obviously not taken the pictures as he was in the background of most of them, looking away. 
These girls had gotten a hold of his phone, taken the pictures and uploaded them. 
This wouldn't bother me normally, at all, but this time it did. 
For the past few weeks he had not let me near his phone, saying that he didn't want my birthday present/ surprise to be ruined, and I respected that. 
The only time he would let me touch his phone would be to change a music track. 
It then progressed to him thinking that the minute I touched his phone I would go through it, and that was never the case! I don't even know his password. 
I then come to the realisation that if these girls have been able to get onto his camera and then Facebook, they must have his password. 
So I message him, questioning him why they are allowed on his phone and I'm not. 
The girl taking the photos answers me.
She instantly starts telling me to inbox her if I have a problem, that she was a borrowing his phone to make a call, before telling me to pipe down. 
Of course, by now I'm mad. 
How dare they?
He obviously knows she has his phone and that she's answered me, why would he allow that? 
After a short disagreement with her, he finally messages me, telling me he hates when I assume things and that he cries himself to sleep because of the way I act. That he loves me, but I make him feel small and worthless when I do this. 
He also said that I push him away every time this happens, but I can't understand why I wouldn't? 
I am prone to being jealous, I will admit, but it's not as bad as he makes it out to be. 
I just don't understand why or how he can trust these "strangers" (because that's what they are) with his phone and password but not me. 
Am I in the wrong? 
I'm fed up with feeling like the bad guy when he's the one letting strangers go through his messages. 
Help?