A $700. electricity bill does seem excessive, but we really do not know how many people shower and use electricity in that house.
May I suggest that you and your boyfriend either get jobs or if you have jobs, why not pay half of the electric bill so you can keep the air conditioning on? I dare you to offer to help pay a bill. At least this way, you can actually SEE the bill for yourself.
In my house, we went on an electricity diet. I changed all bulbs to LED light bulbs. We do not keep our chargers plugged into an outlet unless they are being used. You see, when chargers are plugged in, they draw a current even when not used. So, if you have, say, five people in the house with computers, cell phones and other electronics, you are all drawing electricity and wasting it, so, UNPLUG chargers, all of them....or, put them on a power strip and then turn off the power strip when not in use.
In the main living room area or where you hang out, set up a lamp on a timer to go on at dusk and off around bed time. This way there will be light and everyone is not turning lights on and off and on again, which draws more electricity than keeping a light on. Put LED night lights in hallways and bathrooms and even your bedroom so lights do not need to be turned on and off again so you can navigate around at night.
Only wash clothes in cold water. If possible, set up a clothes line and air dry some clothes that dry quickly. Set the dish washer on air dry. Take shorter showers. Stop using a blow dryer.
For small meals, use a toaster oven rather than the stove oven as that and a microwave uses less electricity.
Get curtains to block out the sun rays, keeping the house cooler. Caulk any cracks around windows and doors. Check them to be sure they are completely closed.
We did all of these things the day our electricity billing cycle began and we saved $40.00 in one month. I gave my two children $20 each when the bill came to congratulate them for their efforts and then told them that because we KNOW it is possible to lower the bill, that from now on, if the bill goes up, they will owe me money. Funny how when I asked THEM to contribute to the bill, our electric bill was lower.
If you are old enough to be living with your boyfriend, then I am going to assume you are an adult. Being an adult while living in someone else's house means you should be paying rent or at least be contributing to the monthly bills. It is expensive to run a household. This is a fact of life and if you want to have air conditioning, then pay for it yourself.