distance

How little distance is too little distance when dealing with students?  I know my mentor teacher keeps some pretty tight boundaries.  I realize this is a somewhat individual question, but I sometimes feel like I relate TOO much with my students.  Am I setting myself up to be undermined as far as discipline later?  I still get on the students' backs to do their work, but I end up "relating"--which is a horrifically cliched movie (the white girl in an urban school "relating" to her students)--that I really set out specifically to avoid, but I somehow find to be my best way of dealing with students.  Any suggestions?