Thinking of doing something that's not so usual as dinner and a movie with your beloved? Then consider the following:
1) Volunteer Work. It can be as simple as repacking goods for recent tragedy victims (and considering we have lots of typhoons, different NGOs and institutions will need all the help they can get) or reading to kids, or attending to some (like at CRIBS). You can even join some NGO or group who is throwing a party for streetchildren or sick children.
2) Limited Budget Date. Determine a budget (say P200) and make sure you both get to eat by just spending that much. Choosing among fishball stands should be fun enough, if you have the spirit for it.
3) Historical Walks. Either attend one of Carlos Celdran tours or just go visit the National Museum... or even Intramuros. The artifacts would be a good talking point, especially if you know some trivia he doesn't.
4) Go to the Races. Car races. Horse races (you need not get all dolled up in equestrian clothing. Go Kart races. Get carried away with the adrenaline high such races bring.
5) Classes. Attend cooking lessons together. Or baking ones. Make a contest out of it on who makes the prettier cupcakes, or the more delicious entrees.
I'd think of more tips and add to these later on. But really the key here is trying something extraordinary without spending so much.