Why is everything "okay" for my boyfriend but not me?

[Cindy]

First lets start off by saying this. I don't have a facebook because my overprotective doesn't let me have one. Let listen to this i asked him if i could have his password and he told me "no because there's convos with his guy friends tht i shouldn't see" *WHICH I RESPECT* so he said that i can look at his phone whenever i'd like when i'm with him. Today, I went thru his messages on facebook. Him and his friend were talking about girls LEFT AND RIGHT. I'm talking about "damn shes hot" or "damn shes fine" Lets make this clear im not jealous because hes never put me in that position. but why is it that when i talk for example about a f-ucking actor (Channing Tatum let's say lol) you start World War 3?!?!? Like we go out to a hookah bar and he gets mad when i look around or if some other guy looks at me o.O its like relax. Or is this just me? cause im certainly not doing anything wrong. Yet him and his bestfriend talk about others girls??? i dont understand -.- He's 19 and I'll be 18 in 3 months. HELP! i would love to hear from both men and women! thank you!
I Loved all these answers! Thanks for your help everyone.
But the only problem is now he's asking me whats wrong and its weird because i often tell him nothing is wrong just so i dont have to talk to him about it. Like i feel like he always has the last word. How can i tell him this? That im upset from what i saw? My major problem is that i can't get over him we've been together too long now. and i dont want to lose him -_-
(I think Im being a pain in the butt to the people who are answering -.-)