I like fine dining, family is redneck

Hey y'all, I'm in the south loop area and my birthday is this weekend. I tend to keep a pretty strict diet but want to treat myself and gf to a nice meal. However my family is coming into town and they don't like to dress up at all, whether at a black tie event or going fishing.

I'm looking for a restaurant featuring a nice ribeye steak or a selection of dry aged beef, preferably downtown, where my dad can still rock a t-shirt and his white new balances and not feel weird. Would also be open to nicer pub style restaurants or old school italian joints.

TL;DR: I want good food but can't take my dad to Bazaar or Kinzies - please help.