As far as Slater knew he hadn't treated Vivian any different than normal and, with Harry's growing anger obvious in the split second before the punch, he had turned to speak to her once more. Perhaps that was fortunate, as when Harry hit him he did not manage to break Slater's nose. Not that it was very hard. Slater stumbled, that was true, but an unprepared man was always going to lose his footing.
After regaining his composure he stood, touching his nose which had blood coming out of one nostril. Wonderful. With a low growl hidden behind a grim smile, Slater spat "I treat her with more respect than you ever did, and it's better to kill 'em than bugger 'em... thanks for showing yourself up tonight though, Fisher. Don't think you've escaped much people's notice now..." he said, gesturing to the crowd of posh people horrified to witness such an assault and now hanging on every word.
"I'll be in the bathroom, Delia," he said, ignoring Vivian for the moment as he walked away. He was far too annyoed and if she wanted to follow him she could.