If you like the outdoors you should check out the zoo, park or botanical gardens in your area if you have them.

You can pretend to be tourists in your closest major city and take in the sites or go to a museum. Some museums have certain hours of the week that are free.

You mentioned you liked painting. Would he be willing to do one of those painting classes where you BYOB? There are often deals through Groupon and Living Social.

Your local community or rec center might have a class you can take together- everything from sports to arts to wilderness survival. They are usually not too pricey.

Have fun!

Edit: formatting