Around here the cinemas open early, so how about maybe hitting the cinema then? It shouldn't be crowded if you go in the late morning/early afternoon. If it's a cinema in a centre, there may even be a restaurant where you have a meal after the film, but before the crowds start picking up.

After that, you could then retreat to somewhere more comfortable for you both for the remainder of the day/evening.

Have a great day whatever you decide to do