I've never heard of bar/club relationships lasting long or even working out well.
One of my friends met a girl at an all ages rave. He's 19 and she's 17 turning 18 soon but the girl is extremely controlling and manipulative of him. They fight constantly and she has the typical hormonal 17 year old girl episodes. Probably doesn't help she's done more drugs than anyone before she was 16 years old.
They've only been together for 5 months and either they're breaking up or they want to run off and get married.