Guys.. When a girl is walking by you, it is not going to help anything that you could want by yelling "Ayo Shawty!!!" It's also not nice to laugh, whether about her or not, because she will automatically think it's her you're laughing at.
HOWEVER... Sometimes, yes, it is okay to laugh at a girl. These times are displayed in the pictures below.
Yes, we might cry if you notice any of these things before us, but sometimes it's just downright funny... As long as it's not me.