Places to hang out with your boyfriend at?

We're fifteen. Been dating nine months. Generally, we hang out three times a week. We go to thE movies all the time. While it's fun.. It's getting expensive. The mall.. We're both at a mutual agreement that it's gotten pretty boring after only a few times going. We usually spend our time at his house, though. We often watch movies or tv there. And boy, are we bored after the movie or show is over.. We rarely come to my house as we get less privacy than at his. We would just sit and talk.. But we literally have ran every subject totally dry. And I'm not exaggerating, either. I am not a summer person at all. So.. I keep us mainly indoors. Occasionally we'll go hang out qt the local school's playground or we'll just take a walk.. But in my opinion, those are better suited for fall and winter, haha. We both don't care for bowling. I enjoy ice skating, but he does not. I absolutely hate swimming.. So none of that. Where else could we go that is indoors? Or what else could we do? Any fun games that you can play are appreciated, too. Or any fun variations of a bunch of cheap things would be nice, too. We've just totally run out of ideas..