
Originally Posted by
citlalli
Hehe... well, if the family is super strict yes, it's best to avoid any sort of slang and bad words altogether

if they are just average strict I think you could get away with slang, and since you're a foreigner they won't be too offended if a "small" bad word slips out of your lips every now and then (like "pinche",) and they may even find it funny; however, it won't be funny at all if one of the big words such as "culero", "cabrón", "verga", "ojete", etc, slips away, those words are to be avoided at any cost, ok?
Concerning "chale", it can have many translations, I think in most cases it's something like "no way!", "yeah... sure!" and it's a bit sarcastic. I found a thread about this word and I thought you may find it interesting:
http://forum.wordreference.com/showthread.php?t=89889