Tennis is a great game to play with your sweetheart or best friend because even when you have nothing, you still have love. Awww. One of the reasons I like tennis so much is it takes only 2 people to play, but you can always go for doubles and play a match with 4 people on the court.
You also don't have to play a "match" - you have other options too. Since serving can be so tedious some days, you can just volley and practice your shots. Plus without having to stop and wait for your partner to serve, you both will stay in motion more for longer periods of time. And that means more exercise!
I also like playing using the no "out-of-bounds" rule and "play with multiple bounce" rule. These two slight modifications will keep you moving as well. It can be hard to keep the little ball in court if you haven't quite figured out how to control the strength of your hit with a little spin. It can be hard to get to those little balls on just one bounce. When you do run out of tennis balls to hit, don't walk - run to gather up all your stray balls. Again, more calories burned.
Many cities and towns have public courts, so you shouldn't be too hard pressed to find a place to play. If you'd like a few more tips check out my tips for the Novice Tennis Player. They should help you find the love of the game.