You have go to remember that he's a 13 year old child so i'm presuming his erratic and rude behavior is down to him probably going through puberty at the current time,all those hormones racing around his body and he's beginning to notice those little changes to his body and wondering why he gets hot and cold flushes and feels so awkward around the girls at school then there's the greasy skin and acne to contend with which will probably result in low self esteem.