Sure they are. We do not allow for sexual relations until a man and wife are married. So before that we are counseled to be careful and not put ourselves in situations that would lead to pre-marital sex, but that does not mean no kissing. We just have to be careful in not letting the kissing go too far. Here is a good place to understand what youth/teenagers are counseled about:http://lds.org/youth/for-the-strength-of-youth?lang=eng

Of course and LDS member is allowed to do whatever they want, we each have free will and can choose what we wish to do with our free will.  
 
The Church does not encourage teenagers dating before the age of 16 nor do they encourage any passionate kissing of any kind because that give temptation a foothold to other more serious sins like fornication.  
 
The official Church Standard as record in the "For the Strength of Youth" Pamphlet states "Do not participate in passionate kissing, lie on top of another person, or touch the private, sacred parts of another person’s body, with or without clothing. Do not allow anyone to do that with you. Do not arouse those emotions in your own body." 
 
While each is free to choose what to do, to obey the Church standards is to not date at all till 16 then only date in group settings, there should be no passionate kissing at all. It is best to avoid any temptation to sin whatsoever.