I have been at my Karate/Eskrima school for 6 years and have attained 2nd degree black. I attend regularly and additionally have a weekly private lesson with my sensei. There are 2 martial arts schools in my smallish to medium sized town, the other being BJJ. I have recently joined this BJJ school and intend to quit my Karate/Eskrima school. The question is should I tell my sensei that I'm leaving his school to join the other, Bjj school. This may hurt his feeling, piss him off, disappoint him or something of this nature. Or should I just leave without telling him about the joining. I want to do the appropriate thing here.