If my body is my own, I can do whatever I want to it. But if it is not my own, if there are liens against it, or allegiances that transcend individual autonomy, then I cannot rightfully pursue any course of behavior. Inappropriate actions against myself are then just as wrong as when done against another person, and exactly what is prohibited is a choice for those higher authorities to decide.
This gives grounds for regulation in matters of sexual conduct, suicide, physical upkeep, and use of time.
Thus categorically, a Christian is not authorized to follow any impulse that comes into their head. We are "free", unrestricted in body to think, speak and move as our mind wishes, and therein is a great dilemma, we are capable of doing far more than we ought. What we ought to do overlaps poorly with what we can do. Thus we must decide what we will do.
We should even think twice before saying "I". Not because we need a bizarre new symbol in its place (such as "this one"), but just to keep in mind the insistent philosophy of personal autonomy attached to saying "I will do this or that." We should not throw away the reality that we are each individual agents controlling the body we inhabit. The whole point to this is to remember our allegiance comes with both benefits and a duty to perform. we Christians are not our own. We where bought with a price. Its not the sort of price you can repay, then go do as you like, free from any oversight or restrictions. Its a price as in a positive value necessary to bring a sum out of the negative. It is like a essential component given where the lack meant utter destruction.
Therefore honor God with your body.