This is a remark made to someone who is thinking about attending a social function where alcohol would be served. 'If you keep going to the barbershop, sooner or later you are going to get a haircut.'
Now for me, I can't imagine getting a haircut if I didn't make the active decision to have one. No barber works for free and I need to pay them, that's one reason. They aren't really that sneaky, I can spot em a mile away, they have those scissors an stuff. And that cape around the neck thing is a dead giveaway too.