Modern life is so hectic and confusing that it can be easy to forget that we are not living in the only era which human history has seen. It is easy to make the mistake of taking for granted that most of the ideas and morals which we hold dear to our hearts are not actually hard and fast truths but merely theories which happen to be popular in this historical moment. What we consider appropriate and inappropriate behavior at the moment is not necessarily due to any kind of objective truth. In reality, our ideas of what is and is not inappropriate are more likely to be due to a variety of factors including economics, technological development, and even the changes in family structure such as the increase in divorces and remarriages which were once notable oddities but are now an unchallenged part of our every day lives.
There is perhaps nowhere in our society where the temporary nature of ideals and morals is more obviously demonstrated that in the sphere of sexuality. What we consider appropriate and inappropriate sexual behavior for various members of society in the western world today is vastly different from what was considered appropriate and inappropriate for, say, people living in classical antiquity. There is no way to be able to know for certain if our attitudes and ideas about sexuality and morality and where these two aspects of life intersect are more or less productive or useful or correct than the ideas held about inappropriate sexual behavior during classical antiquity.
Some people believe that the best way to deal with the fleeting nature of ideals and morals about inappropriate behavior is do whatever you like whenever you like, regardless of society's ideas about what is and is not inappropriate. Other people believe that you should hold fast to the ideals and morals which you were raised with, and should behave according to the ideas of honor according to your family and your traditions. Still others do not even acknowledge that ideas of what is appropriate and what is inappropriate sexual behavior change over time, and maintain that there is absolutely right and absolutely wrong sexual behavior, and that there has been since even before classical antiquity.
When push comes to shove, it seems to be true for many people in modern society that appropriate and inappropriate sexual behavior is ultimately a personal decision. In some ways it is certainly true that nobody can decide what is appropriate and what is inappropriate sexual behavior for another individual, and each individual must make those choices for him or herself. However, when you stop to consider what you feel is appropriate and what is inappropriate sexual behavior, you may find it an interesting exercise to consider the factors which have made your attitudes what they are.
Consider where your morality comes from, and how much of your ideas about inappropriate sexual behavior mark you as a member of your class, age group, or whatever other spheres of society you belong to. Consider how different, for example, your ideas of inappropriate sexual behavior are from those of classical antiquity.