It's really fucking weird. I go up to a couple girls alone, 20 seconds later random dude out of nowhere starts talking to me and sizing me up. He starts getting really close and in my face trying to take my space. I'm friendly and shit maintain my space, and then the girls leave. I find the girls later, and I go was that guy with you? They were like no.. and 10 seconds later, another fucking random ass dude tries to do the same shit to me again! Seriously wtf? This time I ignore the guy, he whispers something in the girls ear and they shake their heads and he walks away. It's just really dumb because dealing with these fuckers makes me lose my focus off the girls. It's like we are sitting there both trying out alpha each other, resulting in making us both look like dbags. What should I do when a guy does that, and how do I prevent it?