I would maybe do Alexandria or Arlington potentially if you are up for long commutes and you want a city feel but it will be brutal and your BF would have to do the making of dinners on the days you are driving probably or get take out. You could train from those areas into Baltimore too. You aren't going to get a "city feel" on a lot of the mid point spots between MD and DC

Go onto google maps and it will give you a better idea on long it would take depending on location for Alexandria/ Arlington but those would have night life. It can be draining I know though, but, doable