What would you wear for a dinner date?

I suppose I am not really into dinner dates. If it was upto me we would just have lunch in a park or get an ice-cream or something, and I'd wear my normal clothes (jeans, T-shirt, hoodie). If I had a boyfriend who wanted to go to posh restaurant I'd do it and I'd wear a dress and high heels even though I hate wearing those things (I wouldn't wear tights though, bleuugh). If he expressed any preference about what I should wear I'd go with that, within reason, because I'd be going on the date for his benefit mainly, so I'd want it to be right for him. I wouldn't spend days of planning on it, I'm just not that kind of person and there's no point pretending I am, but I could be smart occasionally if he wanted that. I'd prefer if we could just be comfortable and be ourselves and do something fun rather than going somewhere formal and paying loads of money for a meal. I don't want a big meal before getting off with someone anyway, I'd just feel fat.