Do you people like, ever read the Bible, or something?
If mere lustful thoughts fall under the category of adultery, then how much more so would actual physical activity? And any guy who thinks that the physical activity of kissing a girl doesn't really arouse any lustful passions, inspire further lustful thoughts, or increase one's susceptibility to temptation to further lustful activity, then they must have pulled an Origen or something. Just because you don't need a condom to kiss, that doesn't mean it's any more acceptable than sex.
I'm no Saint; God knows my past, and I am not inclined to reveal it over the internet, but I can at least say on a personal level, that my fiancee has never even hugged a guy before in her life. And no, that's not because she's fat and ugly; she's actually the most beautiful Copt i've ever seen in my life. She has fair skin and blue eyes (a one in a million chance outcome for a full-blooded Egyptian), and has been hit on enough times to really boil my blood, especially considering that she continues to be hit on during our engagement. The point is however, that she is one of those people who actually decided to save themselves--all of themselves, completely and perfectly--for their future spouse. She went through the effort of resisting those who offered her opportunities, and avoiding circumstances where temptation would have been potentially quite strong, and you can't imagine how much it means to me that she did that, and how ashamed of myself I feel that I couldn't do the same for her.
Like I said earlier, save yourself for your wife, completely, and she'll truly appreciate it. My fiancee and I always joke around about who loved the other first, in a competitive sense, but now I realise, that she truly loved me first, because she loved me before she even met me.