Dude -- you're cramping my style!
What does it mean?
Dude — you're cramping my style!
means that "Dude" is behaving in such a way as to inhibit whatever behavior the speaker is engaging in at the moment — whether that be trying to have a conversation, playing a game, trying to get romantic with a woman, whatever. Say I was in a bar chatting up some hottie and you walked over and started trying to sell me insurance, I might tell you you were cramping my style.
I think this could apply to any intrusive behaviour by another that hinders my natural and usual way of doing things, my lifestyle, the plans I had that I can no longer execute easily.