Is the truth really the best thing?

one of my friends j(his initial) well i mean we tell our secrets to eachother and he did like me and i did like him but should i tell him the truth and be honest that i madeout with his use to be best friend c(j's use to be bestfriends initial) and gave c a bj or do you think j will get mad?and c use to like me too but bc j liked me he wasnt gonna ask me out or anything bc it wud be wrong knowing j liked me and stuff.and j hangs out with this guy tht c doesnt want knowing that me and c hungout or madeout or tht i gave a bj to c shud i tell j what happened between me and c or not?do u think j will get mad?