Using dirty pick-up lines on your guy is one of the best ways to charm him. Many people tend to think that it's a guy's job to initiate every move on his lady. But we're in the 21st century, and many customs are changing. Nowadays, 50/50 is the rule of the game. Sometimes when you like a guy, he may not be aware of your feelings. Therefore, if you fall for him, don't wait, go ahead and throw in some lines. However, remember that not all dirty pick-up lines for guys can be appropriate. So learn to pick the best lines for the moment.