My friend's 7, cannot 7

I never knew how to behave in front of my friend's girlfriends. Its weird basically. If you don't talk to them, you are being unfriendly. If you talk to themtoo much, it seems like you are trying to jio them, which in chinese history, you and her will end up drowning in pig basket. Conclusion? I try to be friendly but not so friendly.
Last week, I went out with a group of friends and this guy brought his girlfriend along. So as usual, I was making my small talks. To be not so friendly, I talk to the group instead of to her, to add in a dash of friendliness I try to make eye contact with her as I glance pass the whole group.
Bad move. Did I mention that we are eating?
So there she was, bending over to eat her noodles and I glance over trying to make eye contact. At that moment, time stood still. In that split second, she looks up and saw me lookin at her and she proceed to look down at her "down blouse". Her right hand drop her chopstick and immediatly hold on to her t shirt. Within that time span before her chopstick reach the table, a tear flow from my cheeks... I'm innocent.. I'm just trying to be friendly.
FYI when guys look at down blouse or up skirt, we never glance. We Always stare.
So should I just act as an unfriendly bastard and ignore the gal friends? Please advise.