He stopped contacting me, should I initiate the contact or let go?

sounds like g/f found out about u 2 talking. that would be why he stopped. contact him say you have been busy. he sounds like his relationship might have been rocky and he was looking for the next possibility and now things are different but maybe he has deep feelings for u and doesnt want to hurt the other girl but i cant say for sure try contacting him and be honest but not to forward while talking bring up the dance and that night and see what he says read between the lines and u got ur answer good luck