It does not require physical contact or even presence.
The worst thing you can do is run in for a kiss, bump your teeth, and then stick your tongue down their throat. You need to be as gentle and as soft as possible in the beginning. If you’re with a girl and you think that she’s interested, go in for something very minimal and soft and see what you get in return. Keep it lip to lip for a while and see where it goes.
You'll feel it inside you that there's something about to happen.
If you start leaning into the person, and he or she doesn't step back or lean back, you know it's time...a special time for a kiss. Imagine kissing the person you think you'll be kissing for the first time. Usually, they go on the person's waist, or if you're embracing, in the middle of your partner's back.
The topic is one that needs to be openly discussed and mutual acceptance of a definition that works for each of them.
I am reminded of my definition for sex: any activity that has as its intent or develops into a sexual stimulation is sex.