Never tell a girl that she cant go out with him or that..
she should and will already know the do's and dont's in a relationship..
she knows she aint supposed to go out with him... She wants you so to say "dont fucking go out with him.. il go kick his ass"... Of course, when you do, you'll drop value....
Just play it cool.. say "whatever, just make sure you dont eat chili right before, so you aint gonna fart, when u sit next to him... you would so embarrass him"
Of course, say this with a smile

...
She wont even notice the movie, or the guy.. she will be thinking "why those he act like that??"... and she will regret haven gone to the teather, if the guys tries any funny business he will get a big NO...
of course, this is best case scenario.. aint sure how it's gonna work..
depends how alpha she knows you are...
PS: This is just my two cents.. but i just think it's not alpha to tell your girl "dont do that, dont be friends with him ect"
If she is complaining about some friends, i just say "hey, you choose who you want to be friends with..." and if she does do something with the guy you just dump her in a snap..
If u in time want to forgive her, it's up to you..
PPS: You could also say, like said above.. "hey make sure you wear big underwear, if he wants to get in your pants he'll run away fast haha.."
PPPS: be alpha..
Also.. In the start i hated it that many boys were talking to my girl.. and she even lives in another country. which made it worse..
But she tells me everything.. like "that guy told me i was beautiful" ect..
She tells me everything.. and thats cause i dont get mad...
On the contrary.. i'm happy that guys want her.. cause i can lay back and think
"Damn, every guy wants to hit my chick... hahahah.. but im the only one that CAN!"
*Borat accent*
You'll never get this you'll never get this allalalalllalala only my alpha BF can..
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http://www.youtube.com/watch?v=UXgOG5TMcqU[/youtube]