What to do when your boyfriend doesn't believe you?

Well I'm no expert about this subject, but i can help. so if he doesn't believe you the fix isn't as easy as it seams. see once you lose someones trust it's hard to regain. now the answer depends on what you did or he thinks you did. first you need to talk about why he doesn't believe you, and then after he tells you fix it! you can try by giving him another persons Word? or better you can try to make it up to them considering they Will not stop pestering over this until he's proven right. i mean what girl doesn't know how stubborn boys are. also if that doesn't work then your in a bad relationship i you can't trust each other self. good luck with that boy and hope he comes to his senses!