Meet me in the slug and lettuce

So I'm meeting my dad in the slug and lettuce. We commonly call it the slag and lettuce due to the old rep it had of being a bit of a meat market. So I'm chatting to my sister and she's saying, so you going somewhere with a knowing glint. Yes say I, meeting pops in the slag and lettuce. Yes she says I know I was just on the phone to him. So are you the slag and he's the lettuce? Astute my sister I think. Bitch!