" and i dont know why a guy can do this to someone else's girlfriend" Not to sound to harsh, but this was just too funny. Listen dude, u must be one of those sojha sajha nepali type, if u know what i mean. Dont blame the dude, blame ur gurl. First of all ppl need to understand that guys dont make any advance to a women unless they get some signs. Its one thing that guys could have less morals than gurls but they would never make a move to hit on someoneles's gurl unless she throws some signs in for him to make moves. He did it cos she gave it to him. Simple as that. As a man u need to be very careful, especially if u have a beautiful woman, lets see ur in a party with ur woman and she leaves u for a sec, then u need to observe her from distance, always know where ur women is at and what is she doing, in a way that she or others wouldnt notice u noticing that. Find out who seem to have more interested in ur women and find out what motives she has with ur woman. Remember there is no such thing as true friendship between opposite sex. The "attraction" always comes into play betn opposite sex friendship. So Question those friendships. Be jealous of her friends in a healthy way. Let her know that ur jealous of such relations. Women are like cows. They will give u milk, be loving and humble., In return u give them protection, love, food, care, affection and such but she always lures for " damlo chutayera baali khana" he he....not a good metaphore but hope u get the point. U should try to know what ur women is up to all the time. Although it nearly impossible to find out what they are up to all the time but atleast we need to try.