I moved from Hants to Merseyside aged 5. I remember trying to sound more Northern (my Northern family are from Liverpool, but lived in St Helens)
The teasing stopped as I became more scouse. Then we moved to Warrington and I landed in the middle of Mancunian exiles who ripped the piss because I was a Scouser.
My accent is now generic Northern 
Throughout all of this my Hants and Dorset family have really taken the piss. They constantly infer that Northerners are less than Southerners, that we are all living in either Coronation St or on the Shameless estate
My Dorset village, Dubarry-clad cousin was once shocked to learn there was countryside in the North....
While the majority is light hearted banter, there are several family members (esp within the Dorset lot) who genuinely believe they are far superior....
My witty retorts include labeling them either Cockernees and calling them Del Boy, or when a Dorset cousin got particularly offensive I replied "I'm sorry, could you repeat that? All I heard was 'oooo arrrr' and something about tractors....?"
She stopped talking to me, could dish it out but didnt know how to be on the receiving end.
Some people (North and South) are just ignorant cunts. The rest are just having a large and you'd be daft to take it personally.
nb: I love everybody from John O'Groats to Lands End puts down spade, hopes hole is big enough 