its so easy for me to look into girls eyes actually I enjoy it a lot and usually the girl will smile back at me or look down, but when it come to guys I can do it but it feel little bit gay! I only do it before a fight, I do it when I want to show the other guy that I am ready to fight him and beat him up sometime I do it : unconsciencely while walking on the street, but in normal conversation I don't look too much into other men's eyes.