DF was christened J.B but his parents always called him B and always intended to - they did not use it as his first name because they did not like the initial B.J!
B is an name unusal outside Wales (we are not welsh and live in Yorkshire), people often mishear it and spell it wrong and DF hated it so when he came to uni in 2002 he decided to start calling himself J.
I have only ever known him as J and so of course only call him that.
He has asked his parents repeatedly to call him J but they refuse, nobody in his family (including his brother!) has made any effort to call him J even though he has made it very clear that he is J now.
Now his mum has complained that we have called him J in our wedding 'save the date' cards and called him J in a big e-mail we sent some people about some wedding stuff.
And he his brother's bestman in August and he asked his brother to refer to him as J.B (as a compromise) on their wedding stuff and on the day and his brother has refused!
AIBU should his family make some effort to use a name that they gave him and he much prefers as opposed to a name he has not used in over 5 years now! And not tell him off for wanting that name!