I was gonna say something that rhymed with 'happy leaded toes', but I didn't want to get another infraction.
<iframe width="420" height="315" src="http://www.youtube.com/embed/93fi3NlriLI" frameborder="0" allowfullscreen></iframe> Well truth be told, everyone acts/talks differently around different people. Think about how you talk in front of your parents, compared to how you talk to you friends or how you talk at work or how you talk on a date. Its natural to change your tone/words to meet the environment you are in. If you were giving a speech in front of professionals, im sure you wouldn't throw in any curse words or use slang.
There's a scientific explanation for that. When they talk slang, they talk with ease. Therefore, they can breath easily and freely. If they can breath easily, oxygen can travel throughout their body more efficiently, giving them 10-20% more strength. Plus, talking slang is accomodated by beautiful movements of hand and body gestures, making them more aerodynamic. Read it from a very reliable source: 9gag