If it's terrible suddenly, you could always nip to the loos and express a little bit off. I was out with a friend whose boobs had suddenly filled up in the restaurant and we snuck off together while she expressed in the toilet cubicle. I was a bit [shocked] as she aimed her milk straight down the loo! But she had been in agony and just let enough go to feel comfortable again. There's no need to be in discomfort on your lovely night out.