I'm going to use a girlfriend who cheated on me
What do you plan on doing to her?
To make my girlfriend jealous and ruin her vacation vacation.
Using people is not a good habit to get into. There is no reason to try and make your girlfriend jealous if you want to have a sound relationship. All this action is doing is hiding some sort of insecurity that you have that you arent talking about it.
I'm going to control her life with my actions.
It is wrong to use people and try to make them miserable. You come off a bit crazy, the relationship is over, please move on. How would you feel being used, I doubt it would be fun.