Do u think its wrong to b bleve wt 1 of your friends tol u bout your ex?

becus she claimed tht hhiz bestfriend tol her tht n my-ex being my bestfriend 2 ididnt think he wud say ne-thimg bad about me so instead i beleved her so do u think iz rong n ididnt ask em becus he did say those things before at one time