Hi.
Are the guys in your class your friends or just people constantly in your environment? It seems like the boys in your class are going through some new phase of communication that is not very constructive and you have every right to be annoyed with it and to report these boys.
Although there is no one right way to react to harassment, and each person needs to respond in her own manner, there might be some better ways to deal with the situation--ways that resolve the problem to your satisfaction without causing more trouble for yourself and your friends. In the future, if you find there are just some things the boys do that you can't ignore (sometimes you don't want to waste your time), you and your friends might want to try giving the offenders a piece of your mind, or reporting them to an appropriate adult--parents, teachers, guidance counselors. Remember too, that hitting a boy, even one who is harassing you, is not the best way to express your anger or frustration with the situation; slapping someone is pretty inappropriate behavior.
People have different levels of tolerance for certain things and it can be hard to figure out where joking crosses the line into just plain sexual harassment (even legal experts have trouble here). I think one good way to understand this better is to really pay attention to your comfort level once the joking starts to make you uncomfortable. You have every right to speak up, leave or let someone else know, depending on the circumstance.
The better you understand your comfort level and the more that you communicate the things that piss you off as soon as they happen, the better off you'll be. You have the right to move about your world freely and not be subjected to this type of crap.
Hopefully the boys in your class will grow out of this phase soon!