The context of the following conversation is Despite the warnings from her parents and other friends, Sasha became Casey's friend.:
Sasha says My friends and parents warned me about Casey.  They think he's trouble..
The friend responds Why do they say that?.
Sasha responds Casey has a reputation of stringing along a lot of girls.  He plays with their emotions..
The friend responds Is that such a bad thing?  He's not a killer or anything..
Sasha responds My family and friends just want me to hang out with better people..
The friend responds Choosing your friends wisely is very important..