First: you need to have a boyfriend that gives you cash/others (a rose appears in a bubble, click it for the prizes)

Use your energy when you need it, but when you need more do this trick:

Click the bubble that your boyfriend gives and there should be a rose, click that bubble. Then take the game away from your iPad/iPhone (by clicking the square button). This should take you to the home screen. Double click the square button again, there should be a grey slide with icons, remove the campus life icon (by holding the icon for a few second, a red circle with a white line should appear through it, tap that button).

Click campus life again and then you should see your boyfriend have that bubble again, if not wait a few seconds.

BUT: this only will work with one boyfriend by one boyfriend, if you have the boyfriends, then only one would have the bubble.
AND: this takes less then 5minutes, depending on how you do it.
ALSO: the bubble will not always give you the energy, sometimes they give you cash only

ENJOY !