I forgot to tell, often "putain" is used when we're angry as "mais putain qu'est ce que tu fais??" = Holyshit, what are you doing?? But you can also use it with good friends, as "putain! qu'est ce que t'es bête" = putain, you're such an idiot" :) You see, putain can be used everywhere! :D

Putain is very often used by french people and in all kind of contexts! I mean, litterally a "putain" is a prostitute, but now we use this word for anything that goes wrong... I'm not sure I'm clear, here are some examples: "Putain! he's late, where is he?" "Où sont ces putains de clés?!" = where are these fucking keys!? I think you can maybe replace fuck/fuckin by putain very often... Or "Putain, ça me saoule!" = Fuck, it sucks! Hope it will help (I need slang too, but in english :))